RELX PLC (SEC Filing Page | XBRL Cloud Viewer | XBRL Instance)

Line Label Object Class Period Type Balance Report ElementName
1 100000 - Document - Document and Entity Information Network

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 http://relx.com/20181231/taxonomy/role/DocumentDocumentAndEntityInformation
2 Implied Table Table

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3 Documentand Entity Information [Abstract] Abstract relx:DocumentandEntityInformationAbstract
4 Document Type Concept (Submission Type) For Period dei:DocumentType
5 Amendment Flag Concept (Yes/No) For Period dei:AmendmentFlag
6 Document Period End Date Concept (Date) For Period dei:DocumentPeriodEndDate
7 Document Fiscal Year Focus Concept (Year) For Period dei:DocumentFiscalYearFocus
8 Document Fiscal Period Focus Concept (Fiscal Period) For Period dei:DocumentFiscalPeriodFocus
9 Trading Symbol Concept (Text/String) For Period dei:TradingSymbol
10 Entity Registrant Name Concept (Text/String) For Period dei:EntityRegistrantName
11 Entity Central Index Key Concept (CIK Number) For Period dei:EntityCentralIndexKey
12 Current Fiscal Year End Date Concept (Month/Day) For Period dei:CurrentFiscalYearEndDate
13 Entity Well-known Seasoned Issuer Concept (Yes/No) For Period dei:EntityWellKnownSeasonedIssuer
14 Entity Current Reporting Status Concept (Yes/No) For Period dei:EntityCurrentReportingStatus
15 Entity Filer Category Concept (Filer Category) For Period dei:EntityFilerCategory
16 Entity Common Stock, Shares Outstanding Concept (Shares) As Of dei:EntityCommonStockSharesOutstanding
17 Entity Emerging Growth Company Concept (Yes/No) For Period dei:EntityEmergingGrowthCompany
18 Entity Shell Company Concept (Yes/No) For Period dei:EntityShellCompany
19 100010 - Statement - Consolidated Income Statement Network

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20 Statement [Table] Table

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21 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
22 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
23 RELX PLC [member] Member relx:RELXPLCMember
24 Statement [Line Items] LineItems us-gaap:StatementLineItems
25 Revenue Concept (Monetary) For Period Credit ifrs-full:Revenue
26 Cost of sales Concept (Monetary) For Period Debit ifrs-full:CostOfSales
27 Gross profit Concept (Monetary) For Period Credit ifrs-full:GrossProfit
28 Selling and distribution costs Concept (Monetary) For Period Debit relx:SellingAndDistributionCosts
29 Administration and other expenses Concept (Monetary) For Period Debit ifrs-full:GeneralAndAdministrativeExpense
30 Share of results of joint ventures Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfContinuingOperationsOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
31 Operating profit Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromOperatingActivities
32 Finance income Concept (Monetary) For Period Credit ifrs-full:FinanceIncome
33 Finance costs Concept (Monetary) For Period Debit ifrs-full:FinanceCosts
34 Net finance costs Concept (Monetary) For Period Credit ifrs-full:FinanceIncomeCost
35 Disposals and other non-operating items Concept (Monetary) For Period Credit relx:GainLossOnDisposalsAndOtherNonOperatingItems
36 Profit before tax Concept (Monetary) For Period Credit ifrs-full:ProfitLossBeforeTax
37 Current tax Concept (Monetary) For Period Debit ifrs-full:CurrentTaxExpenseIncome
38 Deferred tax Concept (Monetary) For Period Debit ifrs-full:DeferredTaxExpenseIncome
39 Tax expense Concept (Monetary) For Period Debit ifrs-full:IncomeTaxExpenseContinuingOperations
40 Net profit for the year Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
41 Attributable to: Abstract ifrs-full:ProfitLossAttributableToAbstract
42 RELX PLC shareholders Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToOwnersOfParent
43 Non-controlling interests Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToNoncontrollingInterests
44 Net profit for the year Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
45 Earnings per share Abstract ifrs-full:EarningsPerShareAbstract
46 Basic earnings per share Abstract ifrs-full:BasicEarningsPerShareAbstract
47 Basic earnings per share Concept (Share) For Period ifrs-full:BasicEarningsLossPerShare
48 Diluted earnings per share Abstract ifrs-full:DilutedEarningsPerShareAbstract
49 Diluted earnings per share Concept (Share) For Period ifrs-full:DilutedEarningsLossPerShare
50 100030 - Statement - Consolidated Statement of Comprehensive Income Network

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 http://relx.com/20181231/taxonomy/role/StatementConsolidatedStatementOfComprehensiveIncome
51 Implied Table Table

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52 Statement Of Comprehensive Income [Abstract] Abstract ifrs-full:StatementOfComprehensiveIncomeAbstract
53 Net profit for the year Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
54 Items that will not be reclassified to profit or loss: Abstract ifrs-full:ComponentsOfOtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTaxAbstract
55 Actuarial (losses)/gains on defined benefit pension schemes Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans
56 Tax on items that will not be reclassified to profit or loss Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLoss
57 Total items that will not be reclassified to profit or loss Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax
58 Items that may be reclassified subsequently to profit or loss: Abstract ifrs-full:ComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTaxAbstract
59 Exchange differences on translation of foreign operations Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeBeforeTaxExchangeDifferencesOnTranslation
60 Fair value movements on cash flow hedges Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnCashFlowHedgesBeforeTax
61 Transfer to net profit from cash flow hedge reserve Concept (Monetary) For Period Debit ifrs-full:ReclassificationAdjustmentsOnCashFlowHedgesBeforeTax
62 Tax on items that may be reclassified to profit or loss Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLoss
63 Total items that may be reclassified to profit or loss Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax
64 Other comprehensive income/(loss) for the year Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncome
65 Total comprehensive income for the year Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncome
66 Attributable to: Abstract ifrs-full:ComprehensiveIncomeAttributableToAbstract
67 RELX PLC shareholders Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncomeAttributableToOwnersOfParent
68 Non-controlling interests Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncomeAttributableToNoncontrollingInterests
69 Total comprehensive income for the year Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncome
70 100050 - Statement - Consolidated Statement of Cash Flows Network

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71 Implied Table Table

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72 Statement Of Cash Flows [Abstract] Abstract ifrs-full:StatementOfCashFlowsAbstract
73 Cash flows from operating activities Abstract ifrs-full:CashFlowsFromUsedInOperatingActivitiesAbstract
74 Cash generated from operations Concept (Monetary) For Period ifrs-full:CashFlowsFromUsedInOperations
75 Interest paid Concept (Monetary) For Period Credit ifrs-full:InterestPaidClassifiedAsOperatingActivities
76 Interest received Concept (Monetary) For Period Debit ifrs-full:InterestReceivedClassifiedAsOperatingActivities
77 Tax paid (net) Concept (Monetary) For Period Credit ifrs-full:IncomeTaxesPaidRefundClassifiedAsOperatingActivities
78 Net cash from operating activities Concept (Monetary) For Period ifrs-full:CashFlowsFromUsedInOperatingActivities
79 Cash flows from investing activities Abstract ifrs-full:CashFlowsFromUsedInInvestingActivitiesAbstract
80 Acquisitions Concept (Monetary) For Period Credit ifrs-full:CashFlowsUsedInObtainingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivities
81 Purchases of property, plant and equipment Concept (Monetary) For Period Credit ifrs-full:PurchaseOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities
82 Expenditure on internally developed intangible assets Concept (Monetary) For Period Credit relx:ExpenditureOnInternallyDevelopedIntangibleAssetsClassifiedAsInvestingActivities
83 Purchase of investments Concept (Monetary) For Period Credit ifrs-full:PurchaseOfOtherLongtermAssetsClassifiedAsInvestingActivities
84 Proceeds from disposals of property, plant and equipment Concept (Monetary) For Period Debit ifrs-full:ProceedsFromSalesOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities
85 Gross proceeds from business disposals Concept (Monetary) For Period Debit ifrs-full:CashFlowsFromLosingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivities
86 Payments on business disposals Concept (Monetary) For Period Credit relx:CashFlowsUsedInLosingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivities
87 Dividends received from joint ventures Concept (Monetary) For Period Debit ifrs-full:DividendsReceivedFromJointVenturesClassifiedAsInvestingActivities
88 Net cash used in investing activities Concept (Monetary) For Period Debit ifrs-full:CashFlowsFromUsedInInvestingActivities
89 Cash flows from financing activities Abstract ifrs-full:CashFlowsFromUsedInFinancingActivitiesAbstract
90 Dividends paid to shareholders of RELX PLC Concept (Monetary) For Period Credit ifrs-full:DividendsPaidToEquityHoldersOfParentClassifiedAsFinancingActivities
91 Distributions to non-controlling interests Concept (Monetary) For Period Credit ifrs-full:DividendsPaidToNoncontrollingInterestsClassifiedAsFinancingActivities
92 Increase/(decrease) in short-term bank loans, overdrafts and commercial paper Concept (Monetary) For Period Debit relx:IncreaseDecreaseInShorttermBankLoansOverdraftsAndCommercialPaper
93 Issuance of term debt Concept (Monetary) For Period Debit ifrs-full:ProceedsFromBorrowingsClassifiedAsFinancingActivities
94 Repayment of term debt Concept (Monetary) For Period Credit ifrs-full:RepaymentsOfBorrowingsClassifiedAsFinancingActivities
95 Repayment of leases Concept (Monetary) For Period Credit ifrs-full:PaymentsOfLeaseLiabilitiesClassifiedAsFinancingActivities
96 Receipts in respect of subleases Concept (Monetary) For Period Debit relx:ProceedsFromSubleasesClassifiedAsFinancingActivities
97 Repurchase of ordinary shares Concept (Monetary) For Period Credit ifrs-full:PaymentsToAcquireOrRedeemEntitysShares
98 Purchase of shares by Employee Benefit Trust Concept (Monetary) For Period Credit relx:PaymentsForPurchaseOfEmployeeBenefitTrustSharesClassifiedAsFinancingActivities
99 Proceeds on issue of ordinary shares Concept (Monetary) For Period Debit ifrs-full:ProceedsFromIssuingShares
100 Net cash used in financing activities Concept (Monetary) For Period Debit ifrs-full:CashFlowsFromUsedInFinancingActivities
101 Increase/(decrease) in cash and cash equivalents Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges
102 Movement in cash and cash equivalents Abstract ifrs-full:EffectOfExchangeRateChangesOnCashAndCashEquivalentsAbstract
103 At start of year Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
104 Increase/(decrease) in cash and cash equivalents Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges
105 Exchange translation differences Concept (Monetary) For Period Debit ifrs-full:EffectOfExchangeRateChangesOnCashAndCashEquivalents
106 At end of year Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
107 100060 - Statement - Consolidated Statement of Financial Position Network

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108 Implied Table Table

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109 Statement Of Financial Position [Abstract] Abstract ifrs-full:StatementOfFinancialPositionAbstract
110 Non-current assets Abstract ifrs-full:NoncurrentAssetsAbstract
111 Goodwill Concept (Monetary) As Of Debit ifrs-full:Goodwill
112 Intangible assets Concept (Monetary) As Of Debit ifrs-full:IntangibleAssetsOtherThanGoodwill
113 Investments in joint ventures Concept (Monetary) As Of Debit ifrs-full:InvestmentsInJointVentures
114 Other investments Concept (Monetary) As Of Debit ifrs-full:OtherNoncurrentFinancialAssets
115 Property, plant and equipment Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipment
116 Right of use assets Concept (Monetary) As Of Debit ifrs-full:RightofuseAssets
117 Deferred tax assets Concept (Monetary) As Of Debit ifrs-full:DeferredTaxAssets
118 Net pension assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentRecognisedAssetsDefinedBenefitPlan
119 Derivative financial instruments Concept (Monetary) As Of Debit ifrs-full:NoncurrentDerivativeFinancialAssets
120 Non-current assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentAssets
121 Current assets Abstract ifrs-full:CurrentAssetsAbstract
122 Inventories and pre-publication costs Concept (Monetary) As Of Debit relx:InventoriesAndPrepublicationCosts
123 Trade and other receivables Concept (Monetary) As Of Debit ifrs-full:TradeAndOtherCurrentReceivables
124 Derivative financial instruments Concept (Monetary) As Of Debit ifrs-full:CurrentDerivativeFinancialAssets
125 Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
126 Current assets Concept (Monetary) As Of Debit ifrs-full:CurrentAssets
127 Assets held for sale Concept (Monetary) As Of Debit ifrs-full:NoncurrentAssetsOrDisposalGroupsClassifiedAsHeldForSaleOrAsHeldForDistributionToOwners
128 Total assets Concept (Monetary) As Of Debit ifrs-full:Assets
129 Current liabilities Abstract ifrs-full:CurrentLiabilitiesAbstract
130 Trade and other payables Concept (Monetary) As Of Credit ifrs-full:TradeAndOtherCurrentPayables
131 Derivative financial instruments Concept (Monetary) As Of Credit ifrs-full:CurrentDerivativeFinancialLiabilities
132 Borrowings Concept (Monetary) As Of Credit ifrs-full:CurrentPortionOfLongtermBorrowings
133 Taxation Concept (Monetary) As Of Credit ifrs-full:CurrentTaxLiabilitiesCurrent
134 Provisions Concept (Monetary) As Of Credit ifrs-full:CurrentProvisions
135 Current liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentLiabilitiesOtherThanLiabilitiesIncludedInDisposalGroupsClassifiedAsHeldForSale
136 Non-current liabilities Abstract ifrs-full:NoncurrentLiabilitiesAbstract
137 Derivative financial instruments Concept (Monetary) As Of Credit ifrs-full:NoncurrentDerivativeFinancialLiabilities
138 Borrowings Concept (Monetary) As Of Credit ifrs-full:LongtermBorrowings
139 Deferred tax liabilities Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilities
140 Net pension obligations Concept (Monetary) As Of Credit ifrs-full:NoncurrentRecognisedLiabilitiesDefinedBenefitPlan
141 Provisions Concept (Monetary) As Of Credit ifrs-full:NoncurrentProvisions
142 Non-current liabilities Concept (Monetary) As Of Credit ifrs-full:NoncurrentLiabilities
143 Liabilities associated with assets held for sale Concept (Monetary) As Of Credit ifrs-full:LiabilitiesIncludedInDisposalGroupsClassifiedAsHeldForSale
144 Total liabilities Concept (Monetary) As Of Credit ifrs-full:Liabilities
145 Net assets Concept (Monetary) As Of Debit ifrs-full:NetAssetsLiabilities
146 Capital and reserves Abstract ifrs-full:EquityAbstract
147 Share capital Concept (Monetary) As Of Credit ifrs-full:IssuedCapital
148 Share premium Concept (Monetary) As Of Credit ifrs-full:SharePremium
149 Shares held in treasury Concept (Monetary) As Of Debit ifrs-full:TreasuryShares
150 Translation reserve Concept (Monetary) As Of Credit ifrs-full:ReserveOfExchangeDifferencesOnTranslation
151 Other reserves Concept (Monetary) As Of Credit relx:RetainedEarningsAndOtherReserves
152 Shareholders’ equity Concept (Monetary) As Of Credit ifrs-full:EquityAttributableToOwnersOfParent
153 Non-controlling interests Concept (Monetary) As Of Credit ifrs-full:NoncontrollingInterests
154 Total equity Concept (Monetary) As Of Credit ifrs-full:Equity
155 100070 - Statement - Consolidated Statement of Changes in Equity Network

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156 Statement Of Changes In Equity [Table] Table

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 ifrs-full:StatementOfChangesInEquityTable
157 Components of equity [axis] Axis ifrs-full:ComponentsOfEquityAxis
158 Equity [member] Member ifrs-full:EquityMember
159 Share capital [member] Member ifrs-full:IssuedCapitalMember
160 Share premium [member] Member ifrs-full:SharePremiumMember
161 Shares held in treasury [member] Member ifrs-full:TreasurySharesMember
162 Translation reserve [member] Member ifrs-full:ReserveOfExchangeDifferencesOnTranslationMember
163 Other reserves [member] Member relx:RetainedEarningsAndOtherReservesMember
164 Shareholders' equity [member] Member ifrs-full:EquityAttributableToOwnersOfParentMember
165 Non-controlling interests [member] Member ifrs-full:NoncontrollingInterestsMember
166 Statement Of Changes In Equity [Line Items] LineItems ifrs-full:StatementOfChangesInEquityLineItems
167 Equity at beginning of period Concept (Monetary) As Of Credit ifrs-full:Equity
168 Impact of adoption of new standards Concept (Monetary) For Period Credit relx:ImpactOfAdoptionOfNewStandards
169 Total comprehensive income for the year Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncome
170 Dividends paid Concept (Monetary) For Period Debit ifrs-full:DividendsPaid
171 Issue of ordinary shares, net of expenses Concept (Monetary) For Period Credit ifrs-full:IssueOfEquity
172 Repurchase of ordinary shares Concept (Monetary) For Period Debit ifrs-full:PurchaseOfTreasuryShares
173 Cancellation of shares Concept (Monetary) For Period Credit ifrs-full:CancellationOfTreasuryShares
174 Increase in share based remuneration reserve (net of tax) Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughSharebasedPaymentTransactions
175 Settlement of share awards Concept (Monetary) For Period Credit relx:IncreaseDecreaseThroughSettlementOfShareAwards
176 Acquisitions Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughAcquisitionOfSubsidiary
177 Disposal of business Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughDisposalOfSubsidiary
178 Exchange differences on translation of capital and reserves Concept (Monetary) For Period Credit relx:IncreaseDecreaseThroughExchangeDifferencesOnTranslationOfCapitalAndReserves
179 Equity at end of period Concept (Monetary) As Of Credit ifrs-full:Equity
180 100080 - Disclosure - Basis of preparation and accounting policies Network

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181 Implied Table Table

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182 Significant Accounting Policies [Abstract] Abstract relx:SignificantAccountingPoliciesAbstract
183 Basis of preparation and accounting policies Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfBasisOfPreparationOfFinancialStatementsExplanatory
184 100090 - Disclosure - Segment analysis Network

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185 Implied Table Table

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186 Disclosure Of Operating Segments [Abstract] Abstract ifrs-full:DisclosureOfOperatingSegmentsAbstract
187 Segment analysis Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfEntitysReportableSegmentsExplanatory
188 100100 - Disclosure - Operating profit Network

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189 Implied Table Table

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190 Operating Profit [Abstract] Abstract relx:OperatingProfitAbstract
191 Operating profit Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfProfitLossFromOperatingActivitiesExplanatory
192 100110 - Disclosure - Auditor’s remuneration Network

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193 Implied Table Table

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194 Auditors Remuneration [Abstract] Abstract ifrs-full:AuditorsRemunerationAbstract
195 Auditor’s remuneration Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfAuditorsRemunerationExplanatory
196 100120 - Disclosure - Personnel Network

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197 Implied Table Table

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198 Disclosure Of Employees [Abstract] Abstract relx:DisclosureOfEmployeesAbstract
199 Personnel Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfInformationAboutEmployeesExplanatory
200 100130 - Disclosure - Pension schemes Network

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201 Implied Table Table

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202 Disclosure Of Defined Benefit Plans [Abstract] Abstract ifrs-full:DisclosureOfDefinedBenefitPlansAbstract
203 Pension schemes Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfEmployeeBenefitsExplanatory
204 100140 - Disclosure - Net finance costs Network

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205 Implied Table Table

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206 Net Finance Costs [Abstract] Abstract relx:NetFinanceCostsAbstract
207 Net finance costs Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfFinanceIncomeExpenseExplanatory
208 100150 - Disclosure - Disposals and other non-operating items Network

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209 Implied Table Table

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210 Disclosure Of Disposals And Nonoperating Items [Abstract] Abstract relx:DisclosureOfDisposalsAndNonoperatingItemsAbstract
211 Disposals and other non-operating items Concept (Text Block (HTML)) For Period relx:DisclosureOfDisposalsAndOtherNonoperatingItemsExplanatory
212 100160 - Disclosure - Taxation Network

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213 Implied Table Table

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214 Major Components Of Tax Expense Income [Abstract] Abstract ifrs-full:MajorComponentsOfTaxExpenseIncomeAbstract
215 Taxation Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfIncomeTaxExplanatory
216 100170 - Disclosure - Earnings per share Network

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217 Implied Table Table

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218 Earnings Per Share [Abstract] Abstract ifrs-full:EarningsPerShareAbstract
219 Earnings per share Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfEarningsPerShareExplanatory
220 100180 - Disclosure - Statement of cash flows Network

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221 Implied Table Table

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222 Disclosure Of Cash Flow Statement [Abstract] Abstract relx:DisclosureOfCashFlowStatementAbstract
223 Statement of cash flows Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfCashFlowStatementExplanatory
224 100190 - Disclosure - Acquisitions Network

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225 Implied Table Table

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226 Disclosure Of Business Combinations [Abstract] Abstract ifrs-full:DisclosureOfBusinessCombinationsAbstract
227 Acquisitions Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfBusinessCombinationsExplanatory
228 100200 - Disclosure - Equity dividends Network

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229 Implied Table Table

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230 Reconciliation Of Number Of Shares Outstanding [Abstract] Abstract ifrs-full:ReconciliationOfNumberOfSharesOutstandingAbstract
231 Equity dividends Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDividendsExplanatory
232 100210 - Disclosure - Goodwill Network

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233 Implied Table Table

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234 Text Block1 [Abstract] Abstract relx:TextBlock1Abstract
235 Goodwill Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfGoodwillExplanatory
236 100220 - Disclosure - Intangible Assets Network

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237 Implied Table Table

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238 Disclosure Of Intangible Assets [Abstract] Abstract ifrs-full:DisclosureOfIntangibleAssetsAbstract
239 Intangible assets Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfIntangibleAssetsExplanatory
240 100230 - Disclosure - Investments Network

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241 Implied Table Table

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242 Disclosure Of Investments [Abstract] Abstract relx:DisclosureOfInvestmentsAbstract
243 Investments Concept (Text Block (HTML)) For Period relx:DisclosureOfInvestmentsExplanatory
244 100240 - Disclosure - Property, plant and equipment Network

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245 Implied Table Table

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246 Disclosure Of Property Plant And Equipment [Abstract] Abstract ifrs-full:DisclosureOfPropertyPlantAndEquipmentAbstract
247 Property, plant and equipment Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfPropertyPlantAndEquipmentExplanatory
248 100250 - Disclosure - Financial instruments Network

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249 Implied Table Table

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250 Disclosure Of Financial Instruments [Abstract] Abstract ifrs-full:DisclosureOfFinancialInstrumentsAbstract
251 Financial instruments Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfFinancialInstrumentsExplanatory
252 100260 - Disclosure - Inventories and pre-publication costs Network

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253 Implied Table Table

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254 Disclosure Of Information About Inventories Explanatory [Abstract] Abstract relx:DisclosureOfInformationAboutInventoriesExplanatoryAbstract
255 Inventories and pre-publication costs Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfInventoriesExplanatory
256 100270 - Disclosure - Trade and other receivables Network

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257 Implied Table Table

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258 Trade And Other Receivables [Abstract] Abstract ifrs-full:TradeAndOtherReceivablesAbstract
259 Trade and other receivables Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfTradeAndOtherReceivablesExplanatory
260 100280 - Disclosure - Trade and other payables Network

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261 Implied Table Table

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262 Trade And Other Payables [Abstract] Abstract ifrs-full:TradeAndOtherPayablesAbstract
263 Trade and other payables Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfTradeAndOtherPayablesExplanatory
264 100290 - Disclosure - Borrowings Network

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265 Implied Table Table

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266 Borrowings By Type [Abstract] Abstract ifrs-full:BorrowingsByTypeAbstract
267 Borrowings Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfBorrowingsExplanatory
268 100300 - Disclosure - Lease arrangements Network

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269 Implied Table Table

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270 Disclosure Of Finance Lease And Operating Lease By Lessee [Abstract] Abstract ifrs-full:DisclosureOfFinanceLeaseAndOperatingLeaseByLesseeAbstract
271 Lease arrangements Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfLeasesExplanatory
272 100310 - Disclosure - Provisions Network

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273 Implied Table Table

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274 Disclosure Of Other Provisions [Abstract] Abstract ifrs-full:DisclosureOfOtherProvisionsAbstract
275 Provisions Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfProvisionsExplanatory
276 100320 - Disclosure - Share capital, share premium and shares held in treasury Network

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277 Implied Table Table

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278 Disclosure Of Classes Of Share Capital [Abstract] Abstract ifrs-full:DisclosureOfClassesOfShareCapitalAbstract
279 Share capital, share premium and shares held in treasury Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfShareCapitalReservesAndOtherEquityInterestExplanatory
280 100330 - Disclosure - Other reserves Network

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281 Implied Table Table

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282 Disclosure Of Other Reserves [Abstract] Abstract relx:DisclosureOfOtherReservesAbstract
283 Other reserves Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfReservesAndOtherEquityInterestExplanatory
284 100340 - Disclosure - Related party transactions Network

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285 Implied Table Table

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286 Disclosure Of Transactions Between Related Parties [Abstract] Abstract ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesAbstract
287 Related party transactions Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfRelatedPartyExplanatory
288 100350 - Disclosure - Exchange rates Network

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289 Implied Table Table

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290 Foreign Exchange Rates [Abstract] Abstract ifrs-full:ForeignExchangeRatesAbstract
291 Exchange rates Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfEffectOfChangesInForeignExchangeRatesExplanatory
292 100360 - Disclosure - Approval of financial statements Network

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293 Implied Table Table

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294 Approval Of Financial Statements [Abstract] Abstract relx:ApprovalOfFinancialStatementsAbstract
295 Approval of financial statements Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfGeneralInformationAboutFinancialStatementsExplanatory
296 100370 - Disclosure - Related undertakings Network

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297 Implied Table Table

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298 Disclosure Of Transactions Between Related Parties [Abstract] Abstract ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesAbstract
299 Related undertakings Concept (Text Block (HTML)) For Period relx:DisclosureOfInterestsInSubsidiariesJointVenturesAssociatesAndOtherSignificantHoldingsExplanatory
300 100380 - Disclosure - Basis of preparation and accounting policies (Policies) Network

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301 Implied Table Table

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302 Significant Accounting Policies [Abstract] Abstract relx:SignificantAccountingPoliciesAbstract
303 Basis of preparation Concept (Text Block (HTML)) For Period relx:DescriptionOfAccountingPolicyForBasisOfPreparationExplanatory
304 Accounting policies Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfChangesInAccountingPoliciesExplanatory
305 Restatement Concept (Text Block (HTML)) For Period relx:RestatementPolicyTextBlock
306 Foreign exchange translation Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForForeignCurrencyTranslationExplanatory
307 Critical judgements and key sources of estimation uncertainty Concept (Text Block (HTML)) For Period relx:DescriptionOfAccountingPolicyForCriticalChangesInAccountingPoliciesExplanatory
308 Other significant accounting policies Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfOtherAccountingPoliciesRelevantToUnderstandingOfFinancialStatements
309 Standards and amendments effective for the year Concept (Text Block (HTML)) For Period relx:DescriptionOfAccountingPolicyForNewStandardsAndAmendmentsForAnnualPeriodExplanatory
310 IFRS 9 – Financial Instruments Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForFinancialInstrumentsExplanatory
311 IFRS 15 – Revenue from Contracts with Customers Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersExplanatory
312 IFRS 16 – Leases (early adoption and therefore effective for the 2018 financial year) Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForLeasesExplanatory
313 Standards, amendments and interpretations not yet effective Concept (Text Block (HTML)) For Period relx:DescriptionOfAccountingPolicyForNewStandardsAmendmentsAndInterpretationsNotYetAdoptedExplanatory
314 Share based remuneration Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForSharebasedPaymentTransactionsExplanatory
315 Inventories accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForMeasuringInventories
316 Borrowings accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForBorrowingsExplanatory
317 Segments accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForSegmentReportingExplanatory
318 Revenue accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForRecognitionOfRevenue
319 Pension accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForEmployeeBenefitsExplanatory
320 Taxation accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForIncomeTaxExplanatory
321 Cash flows accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForCashFlowsExplanatory
322 Goodwill accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForGoodwillExplanatory
323 Intangible assets accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForIntangibleAssetsOtherThanGoodwillExplanatory
324 Investments, other than investments in joint ventures and associates, accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForInvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodExplanatory
325 Investments in joint ventures and associates, accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForInvestmentInAssociatesAndJointVenturesExplanatory
326 Property, plant and equipment accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForPropertyPlantAndEquipmentExplanatory
327 Trade and other payables accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForTradeAndOtherPayablesExplanatory
328 Provisions accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForProvisionsExplanatory
329 Shares held in treasury accounting policy Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForTreasurySharesExplanatory
330 100390 - Disclosure - Basis of preparation and accounting policies (Tables) Network

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331 Implied Table Table

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332 Significant Accounting Policies [Abstract] Abstract relx:SignificantAccountingPoliciesAbstract
333 Summary of Expected Impact on the Income Statement and Statement of Financial Position Concept (Text Block (HTML)) For Period relx:DisclosureOfProFormaFinancialDataExplanatory
334 100400 - Disclosure - Segment analysis (Tables) Network

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335 Implied Table Table

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336 Disclosure Of Operating Segments [Abstract] Abstract ifrs-full:DisclosureOfOperatingSegmentsAbstract
337 Summary of Analysis by Business Segment Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfOperatingSegmentsExplanatory
338 Summary of Analysis of Revenue by Geographical Origin Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfGeographicalAreasExplanatory
339 Summary of Classification of Revenue Concept (Text Block (HTML)) For Period relx:DisclosureOfRevenueAndSegmentInformationExplanatory
340 Summary of Analysis by Business Segment Expenditure Concept (Text Block (HTML)) For Period relx:DisclosureOfDetailedInformationAboutBusinessSegmentExplanatory
341 Summary of Analysis of Non-current Assets by Geographical Location Concept (Text Block (HTML)) For Period relx:DisclosureOfDetailedInformationAboutNonCurrentAssetsByGeographicalLocationExplanatory
342 Summary of Reconciliation of Operating Profit to Adjusted Operating Profit Concept (Text Block (HTML)) For Period relx:DisclosureOfSegmentalInformationForTheConsolidatedIncomeStatementOfContinuingOperationsExplanatory
343 100410 - Disclosure - Operating profit (Tables) Network

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344 Implied Table Table

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345 Operating Profit [Abstract] Abstract relx:OperatingProfitAbstract
346 Disclosure of Detailed Information About Operating Profit Concept (Text Block (HTML)) For Period relx:DisclosureOfItemsIncludedInOperatingProfitExplanatory
347 100420 - Disclosure - Auditor's remuneration (Tables) Network

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348 Implied Table Table

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349 Auditors Remuneration [Abstract] Abstract ifrs-full:AuditorsRemunerationAbstract
350 Disclosure of Detailed Information About Auditors' Remuneration Concept (Text Block (HTML)) For Period relx:DisclosureOfDetailedInformationAboutAuditorsRemunerationExplanatory
351 100430 - Disclosure - Personnel (Tables) Network

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352 Implied Table Table

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353 Disclosure Of Employees [Abstract] Abstract relx:DisclosureOfEmployeesAbstract
354 Disclosure of Detailed Information About Number of People Employed Concept (Text Block (HTML)) For Period relx:DisclosureOfInformationAboutAverageNumberOfEmployeesExplanatory
355 100440 - Disclosure - Pension schemes (Tables) Network

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356 Implied Table Table

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357 Disclosure Of Defined Benefit Plans [Abstract] Abstract ifrs-full:DisclosureOfDefinedBenefitPlansAbstract
358 Schedule of Defined Benefit and Defined Contribution Schemes Concept (Text Block (HTML)) For Period relx:DisclosureOfDefinedBenefitAndDefinedContributionPensionCostsChargedToIncomeExplanatory
359 Schedule of Defined Benefit Pension Schemes Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDefinedBenefitPlansExplanatory
360 Summary of Defined Benefit Pension Expense Concept (Text Block (HTML)) For Period relx:DisclosureOfNetDefinedBenefitLiabilityAssetAssumptionsAndSchemeValuationsExplanatory
361 Summary of Average Life Expectancy Assumptions Concept (Text Block (HTML)) For Period relx:DisclosureOfSensitivityAnalysisForAverageLifeExpectancyAssumptionsExplanatory
362 Amounts Recognised in the Statement of Financial Position in Respect of Defined Benefit Pension Schemes Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfNetDefinedBenefitLiabilityAssetExplanatory
363 Summary of Net Pension Obligations and Net Pension Assets Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfAdditionalInformationAboutDefinedBenefitPlansExplanatory
364 Amounts Recognised in Statement of Comprehensive Income Concept (Text Block (HTML)) For Period relx:DisclosureOfDefinedBenefitPlansRecognizedInComprehensiveIncomeExplanatory
365 Summary of Fair Value of Scheme Assets Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfFairValueOfPlanAssetsExplanatory
366 Sensitivity Analysis of Actuarial Assumptions Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfSensitivityAnalysisForActuarialAssumptionsExplanatory
367 100450 - Disclosure - Net finance costs (Tables) Network

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368 Implied Table Table

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369 Net Finance Costs [Abstract] Abstract relx:NetFinanceCostsAbstract
370 Summary of Net Finance Costs Concept (Text Block (HTML)) For Period relx:DisclosureOfNetFinanceCostsExplanatory
371 100460 - Disclosure - Disposals and other non-operating items (Tables) Network

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372 Implied Table Table

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373 Disclosure Of Disposals And Nonoperating Items [Abstract] Abstract relx:DisclosureOfDisposalsAndNonoperatingItemsAbstract
374 Summary of Disposals and Other Non-operating Items Concept (Text Block (HTML)) For Period relx:DisclosureOfDetailedInformationAboutDisposalsAndOtherNonoperatingItemsExplanatory
375 100470 - Disclosure - Taxation (Tables) Network

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376 Implied Table Table

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377 Major Components Of Tax Expense Income [Abstract] Abstract ifrs-full:MajorComponentsOfTaxExpenseIncomeAbstract
378 Summary of Tax Expense Concept (Text Block (HTML)) For Period relx:DisclosureOfDetailedInformationAboutIncomeTaxExplanatory
379 Weighted Average of Tax Rates Applicable to Accounting Profits and Losses Concept (Text Block (HTML)) For Period relx:DisclosureOfWeightedAverageOfTaxRatesApplicableToAccountingProfitsAndLossesExplanatory
380 Tax Recognised in Other Comprehensive Income or Directly in Equity Concept (Text Block (HTML)) For Period relx:DisclosureOfTaxExpenseRecognisedInOtherComprehensiveIncomeOrDirectlyInEquityExplanatory
381 Summary of Deferred Tax Liabilities and Assets Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsExplanatory
382 Movements in Deferred Tax Liabilities and Assets Concept (Text Block (HTML)) For Period relx:DisclosureOfMovementsInDeferredTaxLiabilitiesAndAssetsExplanatory
383 100480 - Disclosure - Earnings per share (Tables) Network

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384 Implied Table Table

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385 Earnings Per Share [Abstract] Abstract ifrs-full:EarningsPerShareAbstract
386 Summary of Earnings Per Share Concept (Text Block (HTML)) For Period ifrs-full:EarningsPerShareExplanatory
387 Summary of Adjusted Earnings Per Share Concept (Text Block (HTML)) For Period relx:DisclosureOfDetailedInformationAboutAdjustedEarningsPerShareExplanatory
388 Summary of Reconciliation of Adjusted Net Profit Attributable to Parent Concept (Text Block (HTML)) For Period relx:DisclosureOfDetailedInformationAboutReconciliationOfAdjustedNetProfitAttributableToParentExplanatory
389 100490 - Disclosure - Statement of cash flows (Tables) Network

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390 Implied Table Table

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391 Disclosure Of Cash Flow Statement [Abstract] Abstract relx:DisclosureOfCashFlowStatementAbstract
392 Schedule of Reconciliation of Profit Before Tax to Cash Generated from Operations Concept (Text Block (HTML)) For Period relx:DisclosureOfReconciliationOfProfitBeforeTaxToCashGeneratedFromOperationsExplanatory
393 Schedule of Cash Flow on Acquisitions Concept (Text Block (HTML)) For Period relx:DisclosureOfCashFlowOnAcquisitionsExplanatory
394 Schedule of Reconciliation of Net Borrowings Concept (Text Block (HTML)) For Period relx:DisclosureOfReconciliationOfNetBorrowingsExplanatory
395 100500 - Disclosure - Acquisitions (Tables) Network

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396 Implied Table Table

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397 Disclosure Of Business Combinations [Abstract] Abstract ifrs-full:DisclosureOfBusinessCombinationsAbstract
398 Summary of Consideration Paid for Acquiring Assets and Liabilities Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDetailedInformationAboutBusinessCombinationsExplanatory
399 100510 - Disclosure - Equity dividends (Tables) Network

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400 Implied Table Table

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401 Reconciliation Of Number Of Shares Outstanding [Abstract] Abstract ifrs-full:ReconciliationOfNumberOfSharesOutstandingAbstract
402 Summary of Ordinary Dividends Paid Concept (Text Block (HTML)) For Period relx:DisclosureOfDetailedInformationAboutDividendsExplanatory
403 100520 - Disclosure - Goodwill (Tables) Network

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404 Implied Table Table

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405 Disclosure Of Reconciliation Of Changes In Goodwill [Abstract] Abstract ifrs-full:DisclosureOfReconciliationOfChangesInGoodwillAbstract
406 Disclosure Of Reconciliation Of Changes In Goodwill Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfReconciliationOfChangesInGoodwillExplanatory
407 Summary of Goodwill by Segment Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfReconciliationOfChangesInIntangibleAssetsAndGoodwillExplanatory
408 Key Assumptions Used for Each Group of Cash Generating Units Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfInformationForIndividualAssetOrCashgeneratingUnitWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesExplanatory
409 100530 - Disclosure - Intangible assets (Tables) Network

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410 Implied Table Table

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411 Disclosure Of Intangible Assets [Abstract] Abstract ifrs-full:DisclosureOfIntangibleAssetsAbstract
412 Summary of Intangible Assets Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDetailedInformationAboutIntangibleAssetsExplanatory
413 100540 - Disclosure - Investments (Tables) Network

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414 Implied Table Table

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415 Disclosure Of Investments [Abstract] Abstract relx:DisclosureOfInvestmentsAbstract
416 Summary of Investments Concept (Text Block (HTML)) For Period relx:DisclosureOfDetailedInformationAboutInvestmentsExplanatory
417 Summary of Analysis of Changes in Carrying Value of Investments in Joint Ventures Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfJointVenturesExplanatory
418 Summary of Group's Share of Joint Ventures Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfInvestmentsAccountedForUsingEquityMethodExplanatory
419 100550 - Disclosure - Property, plant and equipment (Tables) Network

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420 Implied Table Table

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421 Disclosure Of Property Plant And Equipment [Abstract] Abstract ifrs-full:DisclosureOfPropertyPlantAndEquipmentAbstract
422 Summary of Property, Plant and Equipment Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDetailedInformationAboutPropertyPlantAndEquipmentExplanatory
423 100560 - Disclosure - Financial instruments (Tables) Network

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424 Implied Table Table

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425 Disclosure Of Financial Instruments [Abstract] Abstract ifrs-full:DisclosureOfFinancialInstrumentsAbstract
426 Summary of Remaining Contractual Maturities for Borrowings and Derivative Financial Instruments Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDetailedInformationAboutFinancialInstrumentsExplanatory
427 Summary of Cash Flow Hedges Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDetailedInformationAboutHedgedItemsExplanatory
428 Summary of Gains and Losses on the Borrowings and Related Derivatives Designated as Fair Value Hedges Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfFinancialInstrumentsDesignatedAtFairValueThroughProfitOrLossExplanatory
429 Summary of Movements in the Hedge Reserve Including Gains and Losses on Cash Flow Hedging Instruments Concept (Text Block (HTML)) For Period relx:DisclosureOfmovementsInTheHedgeReserveIncludingGainsAndLossesOnCashFlowHedgingInstrumentsExplanatory
430 Summary of Deferred Gains and Losses on Cash Flow Hedges Currently Expected to Recognised in Future Period Concept (Text Block (HTML)) For Period relx:DisclosureOfDeferredGainsAndLossesOnCashFlowHedgesCurrentlyExpectedToRecognisedInFuturePeriodExplanatory
431 100570 - Disclosure - Inventories and pre-publication costs (Tables) Network

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432 Implied Table Table

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433 Disclosure Of Information About Inventories Explanatory [Abstract] Abstract relx:DisclosureOfInformationAboutInventoriesExplanatoryAbstract
434 Summary of Inventories and Pre-Publication Costs Concept (Text Block (HTML)) For Period relx:DisclosureOfInformationAboutInventoriesExplanatory
435 100580 - Disclosure - Trade and other receivables (Tables) Network

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436 Implied Table Table

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437 Trade And Other Receivables [Abstract] Abstract ifrs-full:TradeAndOtherReceivablesAbstract
438 Summary of Trade and Other Receivables Concept (Text Block (HTML)) For Period relx:DisclosureDetailedInformationOfTradeAndOtherReceivablesExplanatory
439 Summary of Movements in Loss Allowance for Expected Credit Losses Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfAllowanceForCreditLossesExplanatory
440 100590 - Disclosure - Trade and other payables (Tables) Network

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441 Implied Table Table

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442 Trade And Other Payables [Abstract] Abstract ifrs-full:TradeAndOtherPayablesAbstract
443 Summary of Trade and Other Payables Concept (Text Block (HTML)) For Period relx:DisclosureOfDetailedInformationAboutTradeAndOtherPayablesExplanatory
444 100600 - Disclosure - Borrowings (Tables) Network

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445 Implied Table Table

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446 Borrowings By Type [Abstract] Abstract ifrs-full:BorrowingsByTypeAbstract
447 Summary of types of Borrowings both Current and Non-current Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsExplanatory
448 Summary of Repayment Years for Borrowings Concept (Text Block (HTML)) For Period relx:DisclosureOfRepaymentScheduleOfBorrowingsAndDebtSecuritiesExplanatory
449 Analysis of Borrowings by Currency Concept (Text Block (HTML)) For Period relx:DisclosureOfAnalysisOfBorrowingsByCurrencyExplanatory
450 100610 - Disclosure - Lease arrangements (Tables) Network

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451 Implied Table Table

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452 Disclosure Of Finance Lease And Operating Lease By Lessee [Abstract] Abstract ifrs-full:DisclosureOfFinanceLeaseAndOperatingLeaseByLesseeAbstract
453 Summary of right of use assets Concept (Text Block (HTML)) For Period relx:DisclosureOfFinanceLeasesByLesseeExplanatory
454 Summary of lease liability Concept (Text Block (HTML)) For Period relx:DisclosureOfLeaseLiabilityExplanatory
455 Summary of finance lease receivable Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfMaturityAnalysisOfFinanceLeasePaymentsReceivableExplanatory
456 100620 - Disclosure - Provisions (Tables) Network

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457 Implied Table Table

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458 Disclosure Of Other Provisions [Abstract] Abstract ifrs-full:DisclosureOfOtherProvisionsAbstract
459 Summary of Changes in Provisions Concept (Text Block (HTML)) For Period relx:DisclosureOfChangesInProvisionsExplanatory
460 Summary of Provisions Included Within Current and Non-current Liabilities Concept (Text Block (HTML)) For Period relx:DisclosureOfProvisionsIncludedInCurrentAndNoncurrentLiabilitiesExplanatory
461 100630 - Disclosure - Share capital, share premium and shares held in treasury (Tables) Network

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462 Implied Table Table

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463 Disclosure Of Classes Of Share Capital [Abstract] Abstract ifrs-full:DisclosureOfClassesOfShareCapitalAbstract
464 Summary of Share Capital Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfClassesOfShareCapitalExplanatory
465 100640 - Disclosure - Other reserves (Tables) Network

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466 Implied Table Table

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467 Disclosure Of Other Reserves [Abstract] Abstract relx:DisclosureOfOtherReservesAbstract
468 Summary of Other Reserves Concept (Text Block (HTML)) For Period relx:DisclosureOfOtherReservesExplanatory
469 100650 - Disclosure - Related party transactions (Tables) Network

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470 Implied Table Table

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471 Disclosure Of Transactions Between Related Parties [Abstract] Abstract ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesAbstract
472 Summary of Key Management Personnel Remuneration Concept (Text Block (HTML)) For Period relx:DisclosureOfInformationAboutKeyManagementPersonnelRemunerationExplanatory
473 Summary of Executive Directors Remuneration Concept (Text Block (HTML)) For Period relx:DisclosureOfInformationAboutExecutiveDirectorsRemunerationExplanatory
474 Summary of Non-Executive Directors Remuneration Concept (Text Block (HTML)) For Period relx:DisclosureOfInformationAboutNonExecutiveDirectorsRemunerationExplanatory
475 100660 - Disclosure - Exchange rates (Tables) Network

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476 Implied Table Table

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477 Foreign Exchange Rates [Abstract] Abstract ifrs-full:ForeignExchangeRatesAbstract
478 Summary of Exchange Rates in Preparing Consolidated Statements Concept (Text Block (HTML)) For Period relx:DisclosureOfExchangeRatesExplanatory
479 100670 - Disclosure - Related undertakings (Tables) Network

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480 Implied Table Table

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481 Disclosure Of Transactions Between Related Parties [Abstract] Abstract ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesAbstract
482 Summary of Full List of Related Undertakings Concept (Text Block (HTML)) For Period relx:DisclosureOfDetailedInformationAboutInterestsInSubsidiariesJointVenturesAssociatesAndOtherSignificantHoldingsExplanatory
483 100680 - Disclosure - Basis of Preparation and Accounting Policies - Summary of Changes in Proforma Financial Data (Detail) Network

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484 Description Of Expected Impact Of Initial Application Of New Standards Or Interpretations [Table] Table

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485 New IFRSs [axis] Axis ifrs-full:NewIFRSsAxis
486 New IFRSs [member] Member ifrs-full:NewIFRSsMember
487 As reported [member] Member ifrs-full:PreviouslyStatedMember
488 IFRS 9 impact [member] Member relx:IncreaseDecreaseDueToApplicationOfIFRS9Member
489 IFRS 15 impact [member] Member ifrs-full:IncreaseDecreaseDueToApplicationOfIFRS15Member
490 IFRS 16 impact [member] Member relx:IncreaseDecreaseDueToApplicationOfIFRS16Member
491 As restated [member] Member relx:RestatedUnderIFRS9IFRS15AndIFRS16Member
492 Proforma financial data [line items] LineItems ifrs-full:DescriptionOfExpectedImpactOfInitialApplicationOfNewStandardsOrInterpretationsLineItems
493 Revenue Concept (Monetary) For Period Credit ifrs-full:Revenue
494 Adjusted operating profit Concept (Monetary) For Period Credit relx:AdjustedOperatingProfit
495 Reported operating profit Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromOperatingActivities
496 Net finance costs Concept (Monetary) For Period Credit ifrs-full:FinanceIncomeCost
497 Adjusted net profit attributable to RELX PLC shareholders Concept (Monetary) For Period Credit relx:AdjustedProfitLossAttributableToOrdinaryEquityHoldersOfParentEntity
498 Reported net profit attributable to RELX PLC shareholders Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToOwnersOfParent
499 Adjusted EPS Concept (Share) For Period relx:AdjustedBasicAndDilutedEarningsLossPerShare
500 Reported EPS Concept (Share) For Period ifrs-full:BasicEarningsLossPerShare
501 Right of use assets Concept (Monetary) As Of Debit ifrs-full:RightofuseAssets
502 Borrowings (including lease liability) Concept (Monetary) As Of Credit ifrs-full:Borrowings
503 Finance lease receivable Concept (Monetary) As Of Debit ifrs-full:FinanceLeaseReceivables
504 Deferred income Concept (Monetary) As Of Credit ifrs-full:DeferredIncome
505 100690 - Disclosure - Basis of Preparation and Accounting Policies - Additional Information (Detail) Network

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506 Description Of Expected Impact Of Initial Application Of New Standards Or Interpretations [Table] Table

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 ifrs-full:DescriptionOfExpectedImpactOfInitialApplicationOfNewStandardsOrInterpretationsTable
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509 IFRS 9 impact [member] Member relx:IncreaseDecreaseDueToApplicationOfIFRS9Member
510 IFRS 16 impact [member] Member relx:IncreaseDecreaseDueToApplicationOfIFRS16Member
511 Proforma financial data [line items] LineItems ifrs-full:DescriptionOfExpectedImpactOfInitialApplicationOfNewStandardsOrInterpretationsLineItems
512 Borrowings (including lease liability) Concept (Monetary) As Of Credit ifrs-full:Borrowings
513 Decrease in reported operating profit Concept (Monetary) For Period Debit relx:DecreaseInReportedOperatingProfit
514 Decrease in adjusted operating profit Concept (Monetary) For Period Debit relx:DecreaseInAdjustedOperatingProfit
515 Additional right-of-use assets Concept (Monetary) For Period Debit ifrs-full:AdditionsToRightofuseAssets
516 Finance lease receivable Concept (Monetary) As Of Debit ifrs-full:FinanceLeaseReceivables
517 Additional lease liabilities Concept (Monetary) As Of Credit relx:AdditionalLeaseLiabilities
518 Increase in reported operating profit Concept (Monetary) For Period Credit relx:IncreaseInReportedOperatingProfit
519 Increase in adjusted operating profit Concept (Monetary) For Period Credit relx:IncreaseInAdjustedOperatingProfit
520 Increase to finance costs Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForFinanceCosts
521 Reduction In opening retained earnings Concept (Monetary) For Period Debit relx:ReductionInOpeningRetainedEarnings
522 100700 - Disclosure - Segment Analysis - Additional Information (Detail) Network

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523 Disclosure Of Operating Segments [Table] Table

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525 Segments [member] Member ifrs-full:SegmentsMember
526 Exhibitions [member] Member relx:ExhibitionsMember
527 Geographical origin [member] Member relx:GeographicalOriginMember
528 Legal [member] Member relx:LegalMember
529 Risk & business analytics [member] Member relx:RiskAndBusinessAnalyticsMember
530 Range [axis] Axis ifrs-full:RangeAxis
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532 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
533 Top of range [member] Member ifrs-full:TopOfRangeMember
534 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
535 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
536 United Kingdom [member] Member country:GB
537 Joint ventures [axis] Axis ifrs-full:JointVenturesAxis
538 Entity's total for joint ventures [member] Member ifrs-full:EntitysTotalForJointVenturesMember
539 Joint ventures [member] Member ifrs-full:JointVenturesMember
540 Disclosure of operating segments [line items] LineItems ifrs-full:DisclosureOfOperatingSegmentsLineItems
541 Number of segments Concept (Integer) For Period relx:NumberOfOperatingSegments1
542 Number of face to face events conducted Concept (Decimal) For Period relx:NumberOfFaceToFaceEventsConducted
543 Number of countries face to face events conducted Concept (Decimal) For Period relx:NumberOfCountriesFaceToFaceEventsConducted
544 Number of participant in face to face events Concept (Decimal) For Period relx:NumberOfParticipantInFaceToFaceEvents
545 Revenue Concept (Monetary) For Period Credit ifrs-full:Revenue
546 Aggregate amount of transaction price allocated Concept (Monetary) As Of Credit ifrs-full:TransactionPriceAllocatedToRemainingPerformanceObligations
547 Revenue recognition period Concept (xbrli:durationItemType) For Period relx:RevenueRecognitionPeriod
548 Duration of contract Concept (Text/String) For Period relx:DescriptionOfDurationOfContract
549 Amortisation of acquired intangible assets Concept (Monetary) For Period Debit relx:AmortisationOfAcquiredIntangibleAssetsFromJointVentures
550 Non-current assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentAssetsOtherThanFinancialInstrumentsDeferredTaxAssetsPostemploymentBenefitAssetsAndRightsArisingUnderInsuranceContracts
551 Share of results of joint ventures Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
552 100710 - Disclosure - Segment Analysis - Summary of Analysis by Business Segment (Detail) Network

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553 Disclosure Of Operating Segments [Table] Table

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 ifrs-full:DisclosureOfOperatingSegmentsTable
554 Segment consolidation items [axis] Axis ifrs-full:SegmentConsolidationItemsAxis
555 Entity's total for segment consolidation items [member] Member ifrs-full:EntitysTotalForSegmentConsolidationItemsMember
556 Operating segments [member] Member ifrs-full:OperatingSegmentsMember
557 Unallocated amounts [member] Member ifrs-full:UnallocatedAmountsMember
558 Segments [axis] Axis ifrs-full:SegmentsAxis
559 Segments [member] Member ifrs-full:SegmentsMember
560 Scientific, Technical & Medical [member] Member relx:ScientificTechnicalAndMedicalMember
561 Risk & business analytics [member] Member relx:RiskAndBusinessAnalyticsMember
562 Legal [member] Member relx:LegalMember
563 Exhibitions [member] Member relx:ExhibitionsMember
564 Disclosure of operating segments [line items] LineItems ifrs-full:DisclosureOfOperatingSegmentsLineItems
565 Revenue Concept (Monetary) For Period Credit ifrs-full:Revenue
566 Adjusted operating profit Concept (Monetary) For Period Credit relx:AdjustedOperatingProfit
567 100720 - Disclosure - Segment Analysis - Summary of Analysis of Revenue by Geographical Origin (Detail) Network

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568 Disclosure Of Geographical Areas [Table] Table

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 ifrs-full:DisclosureOfGeographicalAreasTable
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570 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
571 North America [member] Member srt:NorthAmericaMember
572 Europe Member srt:EuropeMember
573 Rest of world [member] Member relx:RestOfWorldMember
574 Disclosure Of Geographical Areas [Line Items] LineItems ifrs-full:DisclosureOfGeographicalAreasLineItems
575 Revenue Concept (Monetary) For Period Credit ifrs-full:Revenue
576 100730 - Disclosure - Segment Analysis - Summary of Classification of Revenue (Detail) Network

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577 Disclosure Of Geographical Areas [Table] Table

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 ifrs-full:DisclosureOfGeographicalAreasTable
578 Segment consolidation items [axis] Axis ifrs-full:SegmentConsolidationItemsAxis
579 Entity's total for segment consolidation items [member] Member ifrs-full:EntitysTotalForSegmentConsolidationItemsMember
580 Operating segments [member] Member ifrs-full:OperatingSegmentsMember
581 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
582 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
583 North America [member] Member srt:NorthAmericaMember
584 Europe Member srt:EuropeMember
585 Rest of world [member] Member relx:RestOfWorldMember
586 Segments [axis] Axis ifrs-full:SegmentsAxis
587 Segments [member] Member ifrs-full:SegmentsMember
588 Scientific, Technical & Medical [member] Member relx:ScientificTechnicalAndMedicalMember
589 Risk & business analytics [member] Member relx:RiskAndBusinessAnalyticsMember
590 Legal [member] Member relx:LegalMember
591 Exhibitions [member] Member relx:ExhibitionsMember
592 Products and services [axis] Axis ifrs-full:ProductsAndServicesAxis
593 Products and services [member] Member ifrs-full:ProductsAndServicesMember
594 Electronic [member] Member relx:ElectronicMember
595 Face to face [member] Member relx:FaceToFaceMember
596 Print [member] Member relx:PrintMember
597 Subscriptions [member] Member relx:SubscriptionsMember
598 Transactional [member] Member relx:TransactionalMember
599 Advertising [member] Member relx:AdvertisingsMember
600 Disclosure Of Geographical Areas [Line Items] LineItems ifrs-full:DisclosureOfGeographicalAreasLineItems
601 Total revenue Concept (Monetary) For Period Credit ifrs-full:Revenue
602 Revenue Concept (Monetary) For Period Credit ifrs-full:Revenue
603 100740 - Disclosure - Segment Analysis - Summary of Analysis by Business Segment Expenditure (Detail) Network

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604 Disclosure Of Operating Segments [Table] Table

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 ifrs-full:DisclosureOfOperatingSegmentsTable
605 Segments [axis] Axis ifrs-full:SegmentsAxis
606 Segments [member] Member ifrs-full:SegmentsMember
607 Scientific, Technical & Medical [member] Member relx:ScientificTechnicalAndMedicalMember
608 Risk & business analytics [member] Member relx:RiskAndBusinessAnalyticsMember
609 Legal [member] Member relx:LegalMember
610 Exhibitions [member] Member relx:ExhibitionsMember
611 Disclosure of operating segments [line items] LineItems ifrs-full:DisclosureOfOperatingSegmentsLineItems
612 Expenditure on acquired goodwill and intangible assets Concept (Monetary) For Period Debit relx:ExpenditureOnAcquiredGoodwillAndIntangibleAssets
613 Capital expenditure additions Concept (Monetary) For Period Credit relx:CapitalExpenditureAdditions
614 Amortisation of acquired intangible assets Concept (Monetary) For Period Debit relx:AmortisationOfAcquiredIntangibleAssetsIncludingJointVentures
615 Depreciation and other amortisation Concept (Monetary) For Period Debit relx:DepreciationAndOtherAmortisation
616 100750 - Disclosure - Segment Analysis - Summary of Analysis of Non-current Assets by Geographical Location (Detail) Network

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617 Disclosure Of Geographical Areas [Table] Table

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619 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
620 North America [member] Member srt:NorthAmericaMember
621 Europe Member srt:EuropeMember
622 Rest of world [member] Member relx:RestOfWorldMember
623 Disclosure Of Geographical Areas [Line Items] LineItems ifrs-full:DisclosureOfGeographicalAreasLineItems
624 Non-current assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentAssetsOtherThanFinancialInstrumentsDeferredTaxAssetsPostemploymentBenefitAssetsAndRightsArisingUnderInsuranceContracts
625 100760 - Disclosure - Segment Analysis - Summary of Reconciliation of Operating Profit to Adjusted Operating Profit (Detail) Network

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626 Implied Table Table

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627 Disclosure Of Operating Segments [Abstract] Abstract ifrs-full:DisclosureOfOperatingSegmentsAbstract
628 Operating profit Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromOperatingActivities
629 Adjustments: Abstract ifrs-full:AdjustmentsForReconcileProfitLossAbstract
630 Amortisation of acquired intangible assets Concept (Monetary) For Period Debit relx:AmortisationOfAcquiredIntangibleAssetsIncludingJointVentures
631 Acquisition-related costs Concept (Monetary) For Period Debit ifrs-full:AcquisitionrelatedCostsForTransactionRecognisedSeparatelyFromAcquisitionOfAssetsAndAssumptionOfLiabilitiesInBusinessCombination
632 Reclassification of tax in joint ventures Concept (Monetary) For Period Credit relx:ReclassificationOfTaxInJointVentures
633 Reclassification of finance income in joint ventures Concept (Monetary) For Period Credit relx:ReclassificationOfFinanceIncomeInJointVentures
634 Adjusted operating profit Concept (Monetary) For Period Credit relx:AdjustedOperatingProfit
635 100770 - Disclosure - Operating Profit - Disclosure of Detailed Information About Operating Profit (Detail) Network

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636 Implied Table Table

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637 Analysis Of Income And Expense [Abstract] Abstract ifrs-full:AnalysisOfIncomeAndExpenseAbstract
638 Staff costs Abstract ifrs-full:ClassesOfEmployeeBenefitsExpenseAbstract
639 Wages and salaries Concept (Monetary) For Period Debit ifrs-full:WagesAndSalaries
640 Social security costs Concept (Monetary) For Period Debit ifrs-full:SocialSecurityContributions
641 Pensions Concept (Monetary) For Period Debit relx:PostEmploymentBenefitExpense
642 Share based remuneration Concept (Monetary) For Period Debit ifrs-full:ExpenseFromSharebasedPaymentTransactionsWithEmployees
643 Total staff costs Concept (Monetary) For Period Debit ifrs-full:EmployeeBenefitsExpense
644 Depreciation and amortisation Abstract ifrs-full:DepreciationAndAmortisationExpenseAbstract
645 Amortisation of acquired intangible assets Concept (Monetary) For Period Debit relx:AmortisationOfAcquiredIntangibleAssetsExcludingJointVentures
646 Share of joint ventures' amortisation of acquired intangible assets Concept (Monetary) For Period Debit relx:AmortisationAndImpairmentOfIntangibleAssets
647 Amortisation of internally developed intangible assets Concept (Monetary) For Period Debit relx:AmortisationOfInternallyDevelopedIntangibleAssets
648 Depreciation of property, plant and equipment Concept (Monetary) For Period Debit ifrs-full:DepreciationExpense
649 Depreciation of right of use asset Concept (Monetary) For Period ifrs-full:DepreciationRightofuseAssets
650 Total depreciation and amortisation Concept (Monetary) For Period Debit ifrs-full:DepreciationAndAmortisationExpense
651 Other expenses and income Abstract relx:OtherExpenseAbstract
652 Cost of sales including pre-publication costs and inventory expenses Concept (Monetary) For Period Debit relx:CostOfSalesIncludingPrePublicationCostsAndInventoryExpenses
653 Operating lease rentals expense Concept (Monetary) For Period Debit ifrs-full:RentalExpense
654 Operating lease rentals income Concept (Monetary) For Period Credit ifrs-full:OperatingLeaseIncome
655 100780 - Disclosure - Auditor's Remuneration - Disclosure of Detailed Information About Auditor's Remuneration (Detail) Network

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656 Disclosure Of Auditors Remuneration [Table] Table

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657 Products and services [axis] Axis ifrs-full:ProductsAndServicesAxis
658 Products and services [member] Member ifrs-full:ProductsAndServicesMember
659 Audit-related assurance services [member] Member relx:AuditrelatedAssuranceServicesMember
660 Consulting [member] Member relx:ConsultingServicesMember
661 Due diligence and other transaction-related services [member] Member relx:DueDiligenceAndOtherTransactionrelatedServicesMember
662 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
663 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
664 RELX PLC [member] Member ifrs-full:ParentMember
665 Payable to the auditors of the Group's subsidiaries [member] Member ifrs-full:SubsidiariesMember
666 Disclosure Of auditors remuneration [line items] LineItems relx:DisclosureOfAuditorsRemunerationLineItems
667 Auditors' remuneration Abstract ifrs-full:AuditorsRemunerationAbstract
668 Payable to the auditors Concept (Monetary) For Period Debit ifrs-full:AuditorsRemuneration
669 Audit services Concept (Monetary) For Period Debit ifrs-full:AuditorsRemunerationForAuditServices
670 Total audit and audit related assurance services Concept (Monetary) For Period Debit relx:AuditorsRemunerationAndAuditServicesRemuneration
671 Tax services Concept (Monetary) For Period Debit ifrs-full:AuditorsRemunerationForTaxServices
672 Other services Concept (Monetary) For Period Debit ifrs-full:AuditorsRemunerationForOtherServices
673 Total non-audit related services Concept (Monetary) For Period Debit relx:AuditorRemunerationForNonauditServices
674 100790 - Disclosure - Auditor's Remuneration - Additional Information (Detail) Network

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675 Disclosure Of Auditors Remuneration [Table] Table

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676 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
677 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
678 RELX PLC and RELX NV [member] Member ifrs-full:ParentMember
679 Disclosure Of auditors remuneration [line items] LineItems relx:DisclosureOfAuditorsRemunerationLineItems
680 Audit related assurance services fee Concept (Monetary) For Period Debit ifrs-full:AuditorsRemunerationForAuditServices
681 100800 - Disclosure - Personnel - Disclosure of Detailed Information About Number of People Employed (Detail) Network

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682 Disclosure Of Number And Average Number Of Employees [Table] Table

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683 Segment consolidation items [axis] Axis ifrs-full:SegmentConsolidationItemsAxis
684 Entity's total for segment consolidation items [member] Member ifrs-full:EntitysTotalForSegmentConsolidationItemsMember
685 Operating segments [member] Member ifrs-full:OperatingSegmentsMember
686 Corporate/shared functions [member] Member ifrs-full:MaterialReconcilingItemsMember
687 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
688 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
689 North America [member] Member srt:NorthAmericaMember
690 United Kingdom [member] Member country:GB
691 Netherlands [member] Member country:NL
692 Rest of Europe [member] Member relx:RestOfEuropeMember
693 Rest of world [member] Member relx:RestOfWorldMember
694 Products and services [axis] Axis ifrs-full:ProductsAndServicesAxis
695 Products and services [member] Member ifrs-full:ProductsAndServicesMember
696 Scientific, Technical & Medical [member] Member relx:ScientificTechnicalAndMedicalMember
697 Risk & business analytics [member] Member relx:RiskAndBusinessAnalyticsMember
698 Legal [member] Member relx:LegalMember
699 Exhibitions [member] Member relx:ExhibitionsMember
700 Disclosure of number and average number of employees [line items] LineItems relx:DisclosureOfNumberAndAverageNumberOfEmployeesLineItems
701 Number of employees Concept (Decimal) As Of ifrs-full:NumberOfEmployees
702 Average number of employees Concept (Decimal) For Period ifrs-full:AverageNumberOfEmployees
703 100810 - Disclosure - Pension Schemes - Additional Information (Detail) Network

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704 Disclosure Of Defined Benefit Plans [Table] Table

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*

 ifrs-full:DisclosureOfDefinedBenefitPlansTable
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706 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
707 UK schemes [member] Member relx:DomesticDefinedBenefitPlanMember
708 Foreign schemes [member] Member relx:ForeignDefinedBenefitPlanMember
709 Defined benefit pension plans [member] Member relx:DefinedBenefitPensionPlansMember
710 Funded scheme [member] Member relx:FundedSchemeMember
711 Unfunded scheme [member] Member relx:UnfundedSchemeMember
712 Maturity [axis] Axis ifrs-full:MaturityAxis
713 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
714 2019-2022 [member] Member relx:LaterThanOneYearsAndNotLaterThanFourYearsMember
715 2020-2023 [member] Member ifrs-full:LaterThanTwoYearsAndNotLaterThanFiveYearsMember
716 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
717 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
718 United Kingdom [member] Member country:GB
719 US [member] Member country:US
720 Disclosure of defined benefit plans [line items] LineItems ifrs-full:DisclosureOfDefinedBenefitPlansLineItems
721 Percentage of actuarial valuations of pension Concept (Percent) As Of ifrs-full:ActuarialAssumptionOfExpectedRatesOfPensionIncreases
722 Additional contributions over a period Concept (xbrli:durationItemType) For Period relx:PeriodForAdditionalContributions
723 Expected pension deficit funding contribution Concept (Monetary) For Period Debit relx:EstimateOfFutureContributionsExpectedToBePaidToPlan
724 Pension cost recognised within operating profit Concept (Monetary) For Period Debit relx:PensionCostRecognisedWithinOperatingProfit
725 Defined benefit obligation Concept (Monetary) As Of Credit ifrs-full:DefinedBenefitObligationAtPresentValue
726 Weighted average duration of defined benefit scheme liabilities Concept (Decimal) For Period ifrs-full:WeightedAverageDurationOfDefinedBenefitObligation
727 Deferred tax assets Concept (Monetary) As Of Debit ifrs-full:DeferredTaxAssets
728 100820 - Disclosure - Pension Schemes - Schedule of Defined Benefit and Defined Contribution Schemes (Detail) Network

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729 Implied Table Table

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730 Disclosure Of Defined Benefit Plans [Abstract] Abstract ifrs-full:DisclosureOfDefinedBenefitPlansAbstract
731 Defined benefit pension expense (net of settlement and past service credits in 2018) Concept (Monetary) For Period Debit ifrs-full:PostemploymentBenefitExpenseDefinedBenefitPlans
732 Defined contribution pension expense Concept (Monetary) For Period Debit ifrs-full:PostemploymentBenefitExpenseDefinedContributionPlans
733 Total Concept (Monetary) For Period Debit relx:PostEmploymentBenefitExpenseRecognisedInOperatingProfit
734 100830 - Disclosure - Pension Schemes - Schedule of Defined Benefit Pension Schemes (Detail) Network

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735 Disclosure Of Defined Benefit Plans [Table] Table

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*

 ifrs-full:DisclosureOfDefinedBenefitPlansTable
736 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
737 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
738 UK schemes [member] Member relx:DomesticDefinedBenefitPlanMember
739 Foreign schemes [member] Member relx:ForeignDefinedBenefitPlanMember
740 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
741 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
742 US [member] Member country:US
743 Disclosure of defined benefit plans [line items] LineItems ifrs-full:DisclosureOfDefinedBenefitPlansLineItems
744 Service cost Concept (Monetary) For Period Credit ifrs-full:CurrentServiceCostNetDefinedBenefitLiabilityAsset
745 Settlement and past service credits Concept (Monetary) For Period Credit ifrs-full:PastServiceCostAndGainsLossesArisingFromSettlementsNetDefinedBenefitLiabilityAsset
746 Defined benefit pension expense Concept (Monetary) For Period Debit ifrs-full:PostemploymentBenefitExpenseDefinedBenefitPlans
747 Net interest on net defined benefit obligation Concept (Monetary) For Period Credit ifrs-full:InterestExpenseIncomeNetDefinedBenefitLiabilityAsset
748 Net defined benefit pension expense Concept (Monetary) For Period Debit relx:PostEmploymentBenefitExpenseDefinedBenefitPlansNetInterest
749 100840 - Disclosure - Pension Schemes - Summary of Defined Benefit Pension Expense (Detail) Network

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750 Disclosure Of Defined Benefit Plans [Table] Table

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*

 ifrs-full:DisclosureOfDefinedBenefitPlansTable
751 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
752 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
753 US [member] Member country:US
754 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
755 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
756 UK schemes [member] Member relx:DomesticDefinedBenefitPlanMember
757 Foreign schemes [member] Member relx:ForeignDefinedBenefitPlanMember
758 Disclosure of defined benefit plans [line items] LineItems ifrs-full:DisclosureOfDefinedBenefitPlansLineItems
759 Discount rate Concept (Percent) As Of ifrs-full:ActuarialAssumptionOfDiscountRates
760 Inflation Concept (Percent) As Of ifrs-full:ActuarialAssumptionOfExpectedRatesOfInflation
761 100850 - Disclosure - Pension Schemes - Summary of Average Life Expectancy Assumptions (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosurePensionSchemesSummaryOfAverageLifeExpectancyAssumptionsDetail
762 Disclosure Of Defined Benefit Plans [Table] Table

*

*

 ifrs-full:DisclosureOfDefinedBenefitPlansTable
763 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
764 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
765 UK schemes [member] Member relx:DomesticDefinedBenefitPlanMember
766 Foreign schemes [member] Member relx:ForeignDefinedBenefitPlanMember
767 Actuarial assumptions [axis] Axis ifrs-full:ActuarialAssumptionsAxis
768 Actuarial assumptions [member] Member ifrs-full:ActuarialAssumptionsMember
769 Member currently aged sixty years [member] Member relx:MemberCurrentlyAgedSixtyYearsMember
770 Member currently aged forty five years [member] Member relx:MemberCurrentlyAgedFortyFiveYearsMember
771 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
772 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
773 US [member] Member country:US
774 United Kingdom [member] Member country:GB
775 Disclosure of defined benefit plans [line items] LineItems ifrs-full:DisclosureOfDefinedBenefitPlansLineItems
776 Male average life expectancy Concept (xbrli:durationItemType) For Period relx:MaleAverageLifeExpectancyAssumptions
777 Female average life expectancy Concept (xbrli:durationItemType) For Period relx:FemaleAverageLifeExpectancyAssumptions
778 100860 - Disclosure - Pension Schemes - Amounts Recognised in the Statement of Financial Position in Respect of Defined Benefit Pension Schemes (Detail) Network

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779 Disclosure Of Net Defined Benefit Liability Asset [Table] Table

*

*

 ifrs-full:DisclosureOfNetDefinedBenefitLiabilityAssetTable
780 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
781 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
782 US [member] Member country:US
783 Net defined benefit liability (asset) [axis] Axis ifrs-full:NetDefinedBenefitLiabilityAssetAxis
784 Net defined benefit liability (asset) [member] Member ifrs-full:NetDefinedBenefitLiabilityAssetMember
785 Present value of defined benefit obligation [member] Member ifrs-full:PresentValueOfDefinedBenefitObligationMember
786 Fair value of scheme assets [member] Member ifrs-full:PlanAssetsMember
787 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
788 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
789 UK schemes [member] Member relx:DomesticDefinedBenefitPlanMember
790 Foreign schemes [member] Member relx:ForeignDefinedBenefitPlanMember
791 Disclosure of net defined benefit liability (asset) [line items] LineItems ifrs-full:DisclosureOfNetDefinedBenefitLiabilityAssetLineItems
792 At start of year Concept (Monetary) As Of Credit ifrs-full:LiabilityAssetOfDefinedBenefitPlans
793 Service cost Concept (Monetary) For Period Credit ifrs-full:CurrentServiceCostNetDefinedBenefitLiabilityAsset
794 Past service credits Concept (Monetary) For Period Credit ifrs-full:PastServiceCostNetDefinedBenefitLiabilityAsset
795 Actuarial gain/(loss) on financial assumptions Concept (Monetary) For Period Debit ifrs-full:ActuarialGainsLossesArisingFromChangesInFinancialAssumptionsNetDefinedBenefitLiabilityAsset
796 Actuarial (loss)/gain arising from experience assumptions Concept (Monetary) For Period Debit ifrs-full:ActuarialGainsLossesArisingFromExperienceAdjustmentsNetDefinedBenefitLiabilityAsset
797 Settlement and past service credits Concept (Monetary) For Period Credit ifrs-full:PastServiceCostAndGainsLossesArisingFromSettlementsNetDefinedBenefitLiabilityAsset
798 Net interest on net defined benefit obligation Concept (Monetary) For Period Credit ifrs-full:InterestExpenseIncomeNetDefinedBenefitLiabilityAsset
799 Return on assets excluding amounts included in interest income Concept (Monetary) For Period Debit ifrs-full:ReturnOnPlanAssetsNetDefinedBenefitLiabilityAsset
800 Contributions by employer Concept (Monetary) For Period Debit ifrs-full:ContributionsToPlanByEmployerNetDefinedBenefitLiabilityAsset
801 Actuarial (losses)/gains on defined benefit pension schemes Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans
802 Contributions by employees Concept (Monetary) For Period Debit ifrs-full:ContributionsToPlanByPlanParticipantsNetDefinedBenefitLiabilityAsset
803 Benefits paid Concept (Monetary) For Period Debit ifrs-full:PaymentsFromPlanNetDefinedBenefitLiabilityAsset
804 Exchange translation differences Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughChangesInForeignExchangeRatesNetDefinedBenefitLiabilityAsset
805 At end of year Concept (Monetary) As Of Credit ifrs-full:LiabilityAssetOfDefinedBenefitPlans
806 Net defined benefit obligation, at the start of the year Concept (Monetary) As Of Credit relx:NetDefinedBenefitObligation
807 Overall net pension obligation Concept (Monetary) As Of Credit relx:NetDefinedBenefitObligation
808 100870 - Disclosure - Pension Schemes - Summary of Net Pension Obligations and Net Pension Assets (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosurePensionSchemesSummaryOfNetPensionObligationsAndNetPensionAssetsDetail
809 Disclosure Of Defined Benefit Plans [Table] Table

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*

 ifrs-full:DisclosureOfDefinedBenefitPlansTable
810 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
811 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
812 US [member] Member country:US
813 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
814 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
815 Foreign schemes [member] Member relx:ForeignDefinedBenefitPlanMember
816 Disclosure of defined benefit plans [line items] LineItems ifrs-full:DisclosureOfDefinedBenefitPlansLineItems
817 Net pension assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentRecognisedAssetsDefinedBenefitPlan
818 Net pension obligation Concept (Monetary) As Of Credit ifrs-full:NoncurrentRecognisedLiabilitiesDefinedBenefitPlan
819 Overall net pension obligation Concept (Monetary) As Of Credit ifrs-full:LiabilityAssetOfDefinedBenefitPlans
820 100880 - Disclosure - Pension Schemes - Amounts Recognised in Statement of Comprehensive Income (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosurePensionSchemesAmountsRecognisedInStatementOfComprehensiveIncomeDetail
821 Disclosure Of Defined Benefit Plans [Table] Table

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*

 ifrs-full:DisclosureOfDefinedBenefitPlansTable
822 Actuarial assumptions [axis] Axis ifrs-full:ActuarialAssumptionsAxis
823 Actuarial assumptions [member] Member ifrs-full:ActuarialAssumptionsMember
824 Discount rates [member] Member ifrs-full:ActuarialAssumptionOfDiscountRatesMember
825 Inflation [member] Member ifrs-full:ActuarialAssumptionOfExpectedRatesOfInflationMember
826 Other actuarial assumptions [member] Member ifrs-full:OtherMaterialActuarialAssumptionsMember
827 Disclosure of defined benefit plans [line items] LineItems ifrs-full:DisclosureOfDefinedBenefitPlansLineItems
828 Gains and losses arising during the year: Abstract ifrs-full:GainLossOnRemeasurementOfNetDefinedBenefitLiabilityAssetAbstract
829 Experience gains/(losses) on scheme liabilities Concept (Monetary) For Period Debit relx:ActuarialGainLossesArisingFromExperienceAdjustmentsDefinedBenefitLiability
830 Experience (losses)/gains on scheme assets Concept (Monetary) For Period Debit relx:ActuarialGainsLossesArisingFromExperienceAdjustmentsDefinedBenefitAsset
831 Actuarial gain/(loss) on financial assumptions Concept (Monetary) For Period Debit ifrs-full:ActuarialGainsLossesArisingFromChangesInFinancialAssumptionsNetDefinedBenefitLiabilityAsset
832 Actuarial (losses)/gains on defined benefit pension schemes Concept (Monetary) For Period Debit ifrs-full:GainLossOnRemeasurementOfNetDefinedBenefitLiabilityAsset
833 Net cumulative losses at start of year Concept (Monetary) As Of Credit ifrs-full:ReserveOfRemeasurementsOfDefinedBenefitPlans
834 Net cumulative losses at end of year Concept (Monetary) As Of Credit ifrs-full:ReserveOfRemeasurementsOfDefinedBenefitPlans
835 100890 - Disclosure - Pension Schemes - Summary of Fair Value of Scheme Assets (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosurePensionSchemesSummaryOfFairValueOfSchemeAssetsDetail
836 Disclosure Of Fair Value Of Plan Assets [Table] Table

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*

 ifrs-full:DisclosureOfFairValueOfPlanAssetsTable
837 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
838 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
839 UK schemes [member] Member relx:DomesticDefinedBenefitPlanMember
840 Foreign schemes [member] Member relx:ForeignDefinedBenefitPlanMember
841 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
842 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
843 US [member] Member country:US
844 Disclosure of fair value of plan assets [line items] LineItems ifrs-full:DisclosureOfFairValueOfPlanAssetsLineItems
845 Equities Concept (Monetary) As Of Debit ifrs-full:EquityInstrumentsAmountContributedToFairValueOfPlanAssets
846 Government bonds Concept (Monetary) As Of Debit relx:DebtInstrumentsAmountContributedToFairValueOfPlanassetsGovernmentBonds
847 Corporate bonds Concept (Monetary) As Of Debit relx:DebtInstrumentsAmountContributedToFairValueOfPlanassetsCorporateBonds
848 Property funds and ground leases Concept (Monetary) As Of Debit ifrs-full:PropertyAmountContributedToFairValueOfPlanAssets
849 Structured debt and direct lending Concept (Monetary) As Of Debit ifrs-full:StructuredDebtAmountContributedToFairValueOfPlanAssets
850 Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalentsAmountContributedToFairValueOfPlanAssets
851 Other Concept (Monetary) As Of Debit ifrs-full:OtherAssetsAmountContributedToFairValueOfPlanAssets
852 Total Concept (Monetary) As Of Debit ifrs-full:PlanAssetsAtFairValue
853 100900 - Disclosure - Pension Schemes - Sensitivity Analysis of Actuarial Assumptions (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosurePensionSchemesSensitivityAnalysisOfActuarialAssumptionsDetail
854 Disclosure Of Sensitivity Analysis For Actuarial Assumptions [Table] Table

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 ifrs-full:DisclosureOfSensitivityAnalysisForActuarialAssumptionsTable
855 Actuarial assumptions [axis] Axis ifrs-full:ActuarialAssumptionsAxis
856 Actuarial assumptions [member] Member ifrs-full:ActuarialAssumptionsMember
857 Actuarial assumption of discount rates [member] Member ifrs-full:ActuarialAssumptionOfDiscountRatesMember
858 Actuarial assumption of expected rates of inflation [member] Member ifrs-full:ActuarialAssumptionOfExpectedRatesOfInflationMember
859 Actuarial assumption of Mortality Rates [member] Member ifrs-full:ActuarialAssumptionOfMortalityRatesMember
860 Disclosure Of Sensitivity Analysis For Actuarial Assumptions [Line Items] LineItems ifrs-full:DisclosureOfSensitivityAnalysisForActuarialAssumptionsLineItems
861 Effect of increase/decrease in actuarial assumption on defined benefit pension obligations Concept (Monetary) As Of Credit relx:IncreaseDecreaseInDefinedBenefitObligationDueToReasonablyPossibleIncreaseDecreaseInActuarialAssumption
862 100910 - Disclosure - Pension Schemes - Sensitivity Analysis of Actuarial Assumptions (Parenthetical) (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosurePensionSchemesSensitivityAnalysisOfActuarialAssumptionsParentheticalDetail
863 Disclosure Of Sensitivity Analysis For Actuarial Assumptions [Table] Table

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 ifrs-full:DisclosureOfSensitivityAnalysisForActuarialAssumptionsTable
864 Actuarial assumptions [axis] Axis ifrs-full:ActuarialAssumptionsAxis
865 Actuarial assumptions [member] Member ifrs-full:ActuarialAssumptionsMember
866 Actuarial assumption of discount rates [member] Member ifrs-full:ActuarialAssumptionOfDiscountRatesMember
867 Actuarial assumption of expected rates of inflation [member] Member ifrs-full:ActuarialAssumptionOfExpectedRatesOfInflationMember
868 Actuarial assumption of Mortality Rates [member] Member ifrs-full:ActuarialAssumptionOfMortalityRatesMember
869 Disclosure Of Sensitivity Analysis For Actuarial Assumptions [Line Items] LineItems ifrs-full:DisclosureOfSensitivityAnalysisForActuarialAssumptionsLineItems
870 Increase/decrease in actuarial assumption, percentage Concept (Percent) As Of relx:PercentageOfReasonablyPossibleIncreaseDecreaseInActuarialAssumption
871 Increase/decrease in actuarial assumption, period Concept (xbrli:durationItemType) For Period relx:PeriodOfReasonablyPossibleIncreaseDecreaseInActuarialAssumption
872 100920 - Disclosure - Net Finance Costs - Summary of Net Finance Costs (Detail) Network

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*

 http://relx.com/20181231/taxonomy/role/DisclosureNetFinanceCostsSummaryOfNetFinanceCostsDetail
873 Implied Table Table

*

*

 implied:Table
874 Net Finance Costs [Abstract] Abstract relx:NetFinanceCostsAbstract
875 Interest on short-term bank loans, overdrafts and commercial paper Concept (Monetary) For Period Debit ifrs-full:InterestExpenseOnBankLoansAndOverdrafts
876 Interest on term debt Concept (Monetary) For Period Debit ifrs-full:InterestExpenseOnDebtInstrumentsIssued
877 Interest on lease liabilities Concept (Monetary) For Period Debit ifrs-full:InterestExpenseOnFinanceLeases
878 Total borrowing costs Concept (Monetary) For Period Debit ifrs-full:BorrowingCostsRecognisedAsExpense
879 Losses on loans and derivatives not designated as hedges Concept (Monetary) For Period Debit ifrs-full:LossesOnChangeInFairValueOfDerivatives
880 Fair value losses on designated fair value hedge relationships Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnHedgingInstrument
881 Net interest on net defined benefit obligation Concept (Monetary) For Period Credit ifrs-full:InterestExpenseIncomeNetDefinedBenefitLiabilityAsset
882 Finance costs Concept (Monetary) For Period Debit ifrs-full:FinanceCosts
883 Interest on bank deposits Concept (Monetary) For Period Credit ifrs-full:InterestIncomeOnDeposits
884 Interest income on net finance lease receivables Concept (Monetary) For Period Credit relx:InterestIncomeOnNetFinanceLeaseReceivables
885 Fair value gains on designated fair value hedge relationships Concept (Monetary) For Period Credit relx:FairValueGainsOnDesignatedFairValueRelationships
886 Gains on loans and derivatives not designated as hedges Concept (Monetary) For Period Credit ifrs-full:GainsOnChangeInFairValueOfDerivatives
887 Finance income Concept (Monetary) For Period Credit ifrs-full:FinanceIncome
888 Net finance costs Concept (Monetary) For Period Credit ifrs-full:FinanceIncomeCost
889 100930 - Disclosure - Net Finance Costs - Additional Information (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosureNetFinanceCostsAdditionalInformationDetail
890 Implied Table Table

*

*

 implied:Table
891 Interest Costs [Abstract] Abstract ifrs-full:InterestCostsAbstract
892 Net gain (loss) on interest rate derivatives designated as cash flow hedges Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnCashFlowHedgesNetOfTax
893 Hedge reserve reclassified to income statement Concept (Monetary) For Period Credit relx:HedgeReserveGainLossReclassifiedToIncomeStatement
894 Gain (loss) related to foreign exchange movements on debt hedges Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnExchangeDifferencesOnTranslationNetOfTax
895 Offset of foreign exchange gains (loss)on the related debt Concept (Monetary) For Period Debit ifrs-full:ReclassificationAdjustmentsOnCashFlowHedgesNetOfTax
896 100940 - Disclosure - Disposals and other non-operating items - Summary of Disposals and Other Non-operating Items (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosureDisposalsAndOtherNonOperatingItemsSummaryOfDisposalsAndOtherNonOperatingItemsDetail
897 Implied Table Table

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 implied:Table
898 Disclosure Of Disposals And Nonoperating Items [Abstract] Abstract relx:DisclosureOfDisposalsAndNonoperatingItemsAbstract
899 Revaluation of investments Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnFinancialAssetsAtFairValueThroughProfitOrLoss
900 (Loss)/Gain on disposal of businesses and assets held for sale Concept (Monetary) For Period Credit relx:GainLossOnDisposalOfBusinessesAndAssetsHeldForSale
901 Net (loss)/gain on disposals and other non-operating items Concept (Monetary) For Period Credit relx:GainLossOnDisposalsAndOtherNonOperatingItems
902 100950 - Disclosure - Taxation - Summary of Tax Expense (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosureTaxationSummaryOfTaxExpenseDetail
903 Disclosure Of Income Tax Expense [Table] Table

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*

 relx:DisclosureOfIncomeTaxExpenseTable
904 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
905 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
906 United Kingdom [member] Member country:GB
907 Netherlands [member] Member country:NL
908 Rest of world [member] Member relx:RestOfWorldMember
909 Disclosure Of Income Tax Expense [Line Items] LineItems relx:DisclosureOfIncomeTaxExpenseLineItems
910 Current tax Abstract ifrs-full:CurrentTaxExpenseIncomeAndAdjustmentsForCurrentTaxOfPriorPeriodsAbstract
911 Current tax Concept (Monetary) For Period Debit ifrs-full:CurrentTaxExpenseIncome
912 Deferred tax Concept (Monetary) For Period Debit ifrs-full:DeferredTaxExpenseIncome
913 Tax expense Concept (Monetary) For Period Debit ifrs-full:IncomeTaxExpenseContinuingOperations
914 100960 - Disclosure - Taxation - Additional Information (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosureTaxationAdditionalInformationDetail
915 Disclosure Of Income Tax Expenses [Table] Table

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*

 relx:DisclosureOfIncomeTaxExpensesTable
916 Range [axis] Axis ifrs-full:RangeAxis
917 Ranges [member] Member ifrs-full:RangesMember
918 Weighted average [member] Member ifrs-full:WeightedAverageMember
919 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
920 Top of range [member] Member ifrs-full:TopOfRangeMember
921 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
922 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
923 United Kingdom [member] Member country:GB
924 US [member] Member country:US
925 Netherlands [member] Member country:NL
926 Non-adjusting events after reporting period [axis] Axis ifrs-full:NonadjustingEventsAfterReportingPeriodAxis
927 Non-adjusting events after reporting period [member] Member ifrs-full:NonadjustingEventsMember
928 Changes in tax rates or tax laws enacted or announced [member] Member ifrs-full:ChangesInTaxRatesOrTaxLawsEnactedOrAnnouncedMember
929 Temporary difference, unused tax losses and unused tax credits [axis] Axis ifrs-full:TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsAxis
930 Temporary difference, unused tax losses and unused tax credits [member] Member ifrs-full:TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsMember
931 Unused trading losses [member] Member relx:UnusedTradingLossesMember
932 Unused tax losses and other temporary differences [member] Member relx:UnusedTaxLossesAndOtherTemporaryDifferencesMember
933 Disclosure Of Income Tax Expenses [Line Items] LineItems relx:DisclosureOfIncomeTaxExpensesLineItems
934 Tax paid (net) Concept (Monetary) For Period Credit ifrs-full:IncomeTaxesPaidRefundClassifiedAsOperatingActivities
935 Applicable tax rate Concept (Percent) For Period ifrs-full:ApplicableTaxRate
936 Federal corporate tax rate Concept (Percent) For Period relx:FederalCorporateTaxRate
937 Deferred tax credit Concept (Monetary) For Period Debit ifrs-full:DeferredTaxExpenseIncomeRelatingToTaxRateChangesOrImpositionOfNewTaxes
938 Reported tax rate Concept (Percent) For Period ifrs-full:AverageEffectiveTaxRate
939 Deferred tax charge in other comprehensive income Concept (Monetary) For Period relx:DeferredTaxExpenseIncomeRecognisedInOtherComprehensiveIncome
940 Unused losses for which no deferred tax asset has been recognised Concept (Monetary) As Of ifrs-full:DeductibleTemporaryDifferencesForWhichNoDeferredTaxAssetIsRecognised
941 Deferred tax asset not recognised Concept (Monetary) As Of Debit relx:UnrecognizedDeferredTaxAsset
942 Unrecognised losses expiration within 10 years Concept (Monetary) As Of Debit relx:UnrecognisedLossesExpirationWithinTenYears
943 Unrecognised losses expiration more than 10 years Concept (Monetary) As Of Debit relx:UnrecognisedLossesExpirationMoreThanTenYears
944 Deferred tax asset not recognised which can only be used to offset future capital gains Concept (Monetary) As Of Debit relx:UnrecognisedDeferredTaxAssetWhichCanBeUsedToOffsetFutureCapitalGains
945 100970 - Disclosure - Taxation - Weighted Average of Tax Rates Applicable to Accounting Profits and Losses (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosureTaxationWeightedAverageOfTaxRatesApplicableToAccountingProfitsAndLossesDetail
946 Implied Table Table

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947 Reconciliation Of Accounting Profit Multiplied By Applicable Tax Rates [Abstract] Abstract ifrs-full:ReconciliationOfAccountingProfitMultipliedByApplicableTaxRatesAbstract
948 Profit before tax Concept (Monetary) For Period Credit ifrs-full:ProfitLossBeforeTax
949 Tax at average applicable rates Concept (Monetary) For Period Debit ifrs-full:TaxExpenseIncomeAtApplicableTaxRate
950 Tax effect of share of results of joint ventures Concept (Monetary) For Period Credit relx:TaxEffectOfShareOfResultsOfJointVentures
951 Expenses not deductible for tax purposes Concept (Monetary) For Period Debit ifrs-full:TaxEffectOfExpenseNotDeductibleInDeterminingTaxableProfitTaxLoss
952 US state taxes Concept (Monetary) For Period Debit ifrs-full:TaxEffectOfForeignTaxRates
953 Non-deductible costs of share based remuneration Concept (Monetary) For Period Debit relx:TaxExpenseReconciliationNondeductibleCostsOfShareBasedRemuneration
954 Non-deductible disposal-related gains and losses Concept (Monetary) For Period Debit relx:TaxExpenseReconciliationNondeductibleDisposalRelatedGainsAndLosses
955 Deferred tax assets of the period not recognised Concept (Monetary) For Period Debit relx:DeferredTaxAssetsOfThePeriodNotRecognised
956 Change in recognition of deferred tax assets or liabilities Concept (Monetary) For Period Debit relx:TaxEffectOfChangeInRecognitionOfDeferredTaxAssetsOrLiabilities
957 Other adjustments in respect of prior periods Concept (Monetary) For Period Debit ifrs-full:OtherTaxEffectsForReconciliationBetweenAccountingProfitAndTaxExpenseIncome
958 Exceptional tax credit Concept (Monetary) For Period Credit relx:ExceptionalTaxCredit
959 Tax expense Concept (Monetary) For Period Debit ifrs-full:IncomeTaxExpenseContinuingOperations
960 Tax at average applicable rates Concept (Percent) For Period ifrs-full:ApplicableTaxRate
961 Tax effect of share of results of joint ventures Concept (Percent) For Period relx:TaxRateEffectOfIncomeOnInvestmentsInAssociatesAndJointVentures
962 Expenses not deductible for tax purposes Concept (Percent) For Period ifrs-full:TaxRateEffectOfExpenseNotDeductibleInDeterminingTaxableProfitTaxLoss
963 US state taxes Concept (Percent) For Period ifrs-full:TaxRateEffectOfForeignTaxRates
964 Non-deductible costs of share based remuneration Concept (Percent) For Period relx:TaxRateEffectOfExpenseNotDeductibleCostsOfShareBasedRemuneration
965 Non-deductible disposal-related gains and losses Concept (Percent) For Period relx:TaxRateEffectOfExpenseNotDeductibleDisposalRelatedGainsAndLosses
966 Deferred tax assets of the period not recognised Concept (Percent) For Period relx:TaxRateEffectOfDeferredTaxAssetsOfThePeriodNotRecognised
967 Change in recognition of deferred tax assets or liabilities Concept (Percent) For Period relx:TaxRateEffectOfChangeInRecognitionOfDeferredTaxAssetsOrLiabilities
968 Other adjustments in respect of prior periods Concept (Percent) For Period ifrs-full:OtherTaxRateEffectsForReconciliationBetweenAccountingProfitAndTaxExpenseIncome
969 Exceptional tax credit Concept (Percent) For Period relx:TaxRateEffectOfExceptionalTaxCredit
970 Tax expense Concept (Percent) For Period ifrs-full:AverageEffectiveTaxRate
971 100980 - Disclosure - Taxation - Tax Recognised in Other Comprehensive Income or Directly in Equity (Detail) Network

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972 Implied Table Table

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973 Income Tax Relating To Components Of Other Comprehensive Income [Abstract] Abstract ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeAbstract
974 Tax on items that may be reclassified to profit or loss Abstract ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossAbstract
975 Tax on actuarial movements on defined benefit pension schemes Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToRemeasurementsOfDefinedBenefitPlansOfOtherComprehensiveIncome
976 Tax on fair value movements on cash flow hedges Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToCashFlowHedgesOfOtherComprehensiveIncome
977 Net tax (debit)/credit recognised in other comprehensive income Concept (Monetary) For Period ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncome
978 Tax credit on share based remuneration recognised directly in equity Concept (Monetary) For Period Debit ifrs-full:CurrentAndDeferredTaxRelatingToItemsChargedOrCreditedDirectlyToEquity
979 100990 - Disclosure - Taxation - Summary of Deferred Tax Liabilities and Assets (Detail) Network

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980 Implied Table Table

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981 Deferred Tax Assets And Liabilities [Abstract] Abstract ifrs-full:DeferredTaxAssetsAndLiabilitiesAbstract
982 Deferred tax assets Concept (Monetary) As Of Debit ifrs-full:DeferredTaxAssets
983 Deferred tax liabilities Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilities
984 Total Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilityAsset
985 101000 - Disclosure - Taxation - Movements in Deferred Tax Liabilities and Assets (Detail) Network

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986 Disclosure of temporary difference, unused tax losses and unused tax credits [line items] Table

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 ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsTable
987 Temporary difference, unused tax losses and unused tax credits [axis] Axis ifrs-full:TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsAxis
988 Temporary difference, unused tax losses and unused tax credits [member] Member ifrs-full:TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsMember
989 Excess of tax allowances over amortisation [member] Member relx:ExcessOfTaxAllowancesOverAmortisationMember
990 Acquired intangible assets [member] Member relx:AcquiredIntangibleAssetsMember
991 Other temporary differences [member] Member ifrs-full:OtherTemporaryDifferencesMember
992 Excess of amortisation over tax allowances [member] Member relx:ExcessOfAmortisationOverTaxAllowancesMember
993 Tax losses carried forward [member] Member relx:TaxLossesCarriedForwardMember
994 Pension balances [member] Member relx:PensionBalancesMember
995 Classes of assets [axis] Axis ifrs-full:ClassesOfAssetsAxis
996 Assets [member] Member ifrs-full:ClassesOfAssetsMember
997 Deferred tax assets [member] Member relx:DeferredTaxAssetsMember
998 Classes of liabilities [axis] Axis ifrs-full:ClassesOfLiabilitiesAxis
999 Liabilities [member] Member ifrs-full:LiabilitiesMember
1000 Deferred tax liabilities [member] Member relx:DeferredTaxLiabilitiesMember
1001 Disclosure Of Temporary Difference Unused Tax Losses And Unused Tax Credits [Line Items] LineItems ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsLineItems
1002 Deferred tax (liability)/asset at start of year Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilityAsset
1003 Credit/(charge) to profit Concept (Monetary) For Period ifrs-full:DeferredTaxExpenseIncomeRecognisedInProfitOrLoss
1004 (Charge)/credit to equity/other comprehensive income Concept (Monetary) For Period ifrs-full:DeferredTaxRelatingToItemsChargedOrCreditedDirectlyToEquity
1005 Acquisitions Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughBusinessCombinationsDeferredTaxLiabilityAsset
1006 Exchange translation differences Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughNetExchangeDifferencesDeferredTaxLiabilityAsset
1007 Deferred tax (liability)/asset at end of year Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilityAsset
1008 101010 - Disclosure - Earnings Per Share - Summary of Earnings Per Share - 2018, 2017 and 2016 (Detail) Network

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1009 Implied Table Table

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 implied:Table
1010 Earnings Per Share [Abstract] Abstract ifrs-full:EarningsPerShareAbstract
1011 Net profit attributable to RELX PLC shareholders Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToOrdinaryEquityHoldersOfParentEntity
1012 Weighted average number of shares, Basic Concept (Shares) For Period ifrs-full:WeightedAverageShares
1013 EPS, Basic Concept (Share) For Period ifrs-full:BasicEarningsLossPerShare
1014 Net profit attributable to RELX PLC shareholders Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToOrdinaryEquityHoldersOfParentEntityIncludingDilutiveEffects
1015 Weighted average number of shares, Diluted Concept (Shares) For Period ifrs-full:AdjustedWeightedAverageShares
1016 EPS, Diluted Concept (Share) For Period ifrs-full:DilutedEarningsLossPerShare
1017 101020 - Disclosure - Earnings Per Share - Summary of Adjusted Earnings Per Share (Detail) Network

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1018 Implied Table Table

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 implied:Table
1019 Earnings Per Share [Abstract] Abstract ifrs-full:EarningsPerShareAbstract
1020 Adjusted net profit attributable to RELX PLC shareholders Concept (Monetary) For Period Credit relx:AdjustedProfitLossAttributableToOrdinaryEquityHoldersOfParentEntity
1021 Weighted average number of shares Concept (Shares) For Period relx:AdjustedWeightedAverageSharesOutstandingBasicAndDiluted
1022 Adjusted EPS Concept (Share) For Period relx:AdjustedBasicAndDilutedEarningsLossPerShare
1023 101030 - Disclosure - Earnings Per Share - Summary of Reconciliation of Adjusted Net Profit Attributable to Parent (Detail) Network

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1024 Implied Table Table

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 implied:Table
1025 Earnings Per Share [Abstract] Abstract ifrs-full:EarningsPerShareAbstract
1026 RELX PLC shareholders Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToOwnersOfParent
1027 Adjustments (post-tax): Abstract relx:AdjustmentsAttributableToParentEntityPostTaxAbstract
1028 Amortisation of acquired intangible assets Concept (Monetary) For Period Debit relx:AmortisationOfAcquiredIntangibleAssetsIncludingJointVenturesPostTax
1029 Acquisition-related costs Concept (Monetary) For Period Debit ifrs-full:AcquisitionrelatedCostsRecognisedAsExpenseForTransactionRecognisedSeparatelyFromAcquisitionOfAssetsAndAssumptionOfLiabilitiesInBusinessCombination
1030 Net financing charge on defined benefit pension schemes Concept (Monetary) For Period Debit relx:NetFinancingChargeOnDefinedBenefitPensionSchemesPostTax
1031 Disposals and other non-operating items Concept (Monetary) For Period Debit relx:AdjustmentsDisposalsAndOtherNonOperatingItemsPostTax
1032 Other deferred tax credits from intangible assets Concept (Monetary) For Period Credit relx:OtherDeferredTaxesAndTaxCreditsFromIntangibleAssetsPostTax
1033 Exceptional tax credit Concept (Monetary) For Period Credit relx:ExceptionalTaxCredit
1034 Adjusted net profit attributable to RELX PLC shareholders Concept (Monetary) For Period Credit relx:AdjustedProfitLossAttributableToOrdinaryEquityHoldersOfParentEntity
1035 101040 - Disclosure - Statement of cash flows - Schedule of Reconciliation of Profit Before Tax to Cash Generated from Operations (Detail) Network

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1036 Implied Table Table

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1037 Disclosure Of Cash Flow Statement [Abstract] Abstract relx:DisclosureOfCashFlowStatementAbstract
1038 Profit before tax Concept (Monetary) For Period Credit ifrs-full:ProfitLossBeforeTax
1039 Disposals and other non-operating items Concept (Monetary) For Period Credit relx:GainLossOnDisposalsAndOtherNonOperatingItems
1040 Net finance costs Concept (Monetary) For Period Credit ifrs-full:FinanceIncomeCost
1041 Operating profit Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromOperatingActivities
1042 Share of results of joint ventures Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfContinuingOperationsOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
1043 Amortisation of acquired intangible assets Concept (Monetary) For Period Debit relx:AmortisationOfAcquiredIntangibleAssetsExcludingJointVentures
1044 Amortisation of internally developed intangible assets Concept (Monetary) For Period Debit relx:AmortisationOfInternallyDevelopedIntangibleAssets
1045 Depreciation of property, plant and equipment Concept (Monetary) For Period Debit ifrs-full:DepreciationExpense
1046 Depreciation of right of use asset Concept (Monetary) For Period ifrs-full:DepreciationRightofuseAssets
1047 Share based remuneration Concept (Monetary) For Period Debit ifrs-full:ExpenseFromSharebasedPaymentTransactionsWithEmployees
1048 Total non-cash items Concept (Monetary) For Period Debit relx:NonCashItems
1049 Decrease/(increase) in inventories and pre-publication costs Concept (Monetary) For Period Debit relx:IncreaseDecreaseInInventoriesAndPrePublicationCosts
1050 Decrease/(increase) in receivables Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForDecreaseIncreaseInTradeAndOtherReceivables
1051 (Decrease)/increase in payables Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForIncreaseDecreaseInTradeAndOtherPayables
1052 Increase in working capital Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseInWorkingCapital
1053 Cash generated from operations Concept (Monetary) For Period ifrs-full:CashFlowsFromUsedInOperations
1054 101050 - Disclosure - Statement of cash flows - Schedule of Cash Flow on Acquisitions (Detail) Network

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1055 Implied Table Table

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*

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1056 Disclosure Of Cash Flow Statement [Abstract] Abstract relx:DisclosureOfCashFlowStatementAbstract
1057 Purchase of businesses Concept (Monetary) As Of Credit ifrs-full:CashTransferred
1058 Investment in joint ventures Concept (Monetary) For Period Credit ifrs-full:OtherCashPaymentsToAcquireInterestsInJointVenturesClassifiedAsInvestingActivities
1059 Deferred payments relating to prior year acquisitions Concept (Monetary) For Period Credit relx:CashFlowsUsedInObtainingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivitiesForPreviousAcquisition
1060 Total Concept (Monetary) For Period Credit ifrs-full:CashFlowsUsedInObtainingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivities
1061 101060 - Disclosure - Statement of cash flows - Schedule of Reconciliation of Net Borrowings (Detail) Network

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*

 http://relx.com/20181231/taxonomy/role/DisclosureStatementOfCashFlowsScheduleOfReconciliationOfNetBorrowingsDetail
1062 Disclosure Of Cash Flow Statement [Table] Table

*

*

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1063 Liabilities arising from financing activities [axis] Axis ifrs-full:LiabilitiesArisingFromFinancingActivitiesAxis
1064 Liabilities arising from financing activities [member] Member ifrs-full:LiabilitiesArisingFromFinancingActivitiesMember
1065 Borrowings [member] Member relx:Borrowings1Member
1066 Related derivative financial instruments [member] Member relx:RelatedDerivativeFinancialInstrumentsMember
1067 finance lease receivable [member] Member relx:FinanceLeaseReceivableMember
1068 Classes of financial assets [axis] Axis ifrs-full:ClassesOfFinancialAssetsAxis
1069 Financial assets, class [member] Member ifrs-full:FinancialAssetsMember
1070 Cash and cash equivalents [member] Member relx:CashAndCashEquivalentMember
1071 Disclosure of Cash Flow Statement [line items] LineItems relx:DisclosureOfCashFlowStatementLineItems
1072 Cash and cash equivalents at start of year Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
1073 Borrowings at start of year Concept (Monetary) As Of Credit ifrs-full:Borrowings
1074 Derivatives at start of year Concept (Monetary) As Of Debit relx:DerivativeFinancialAssetLiability
1075 Net borrowings at start of year Concept (Monetary) As Of Credit relx:NetBorrowings
1076 (Decrease)/increase in cash and cash equivalents Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseInCashAndCashEquivalents
1077 Decrease/(increase) in short-term bank loans, overdrafts and commercial paper Concept (Monetary) For Period Debit ifrs-full:CashFlowsFromUsedInDecreaseIncreaseInShorttermDepositsAndInvestments
1078 Issuance of term debt Concept (Monetary) For Period Debit ifrs-full:ProceedsFromBorrowingsClassifiedAsFinancingActivities
1079 Repayment of term debt Concept (Monetary) For Period Credit ifrs-full:RepaymentsOfBorrowingsClassifiedAsFinancingActivities
1080 Repayment of finance leases Concept (Monetary) For Period Credit ifrs-full:PaymentsOfFinanceLeaseLiabilitiesClassifiedAsFinancingActivities
1081 Change in net borrowings resulting from cash flows Concept (Monetary) For Period Debit ifrs-full:CashFlowsFromUsedInIncreaseDecreaseInCurrentBorrowings
1082 Borrowings in acquired businesses Concept (Monetary) For Period Debit relx:BorrowingsInAcquiredBusinesses
1083 Remeasurement and derecognition of leases Concept (Monetary) For Period Debit relx:RemeasurementAndDerecognitionOfLeases
1084 Inception of leases Concept (Monetary) For Period Credit ifrs-full:IncreaseThroughNewLeasesLiabilitiesArisingFromFinancingActivities
1085 Fair value and other adjustments to borrowings and related derivatives Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughOtherChangesLiabilitiesArisingFromFinancingActivities
1086 Cash and cash equivalents, exchange translation differences Concept (Monetary) For Period Debit ifrs-full:EffectOfExchangeRateChangesOnCashAndCashEquivalents
1087 Exchange translation differences Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughEffectOfChangesInForeignExchangeRatesLiabilitiesArisingFromFinancingActivities
1088 Exchange translation differences Concept (Monetary) For Period Credit relx:IncreaseDecreaseThroughEffectOfChangesInForeignExchangeRatesNetBorrowings
1089 Cash and cash equivalents at end of year Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
1090 Borrowings at end of year Concept (Monetary) As Of Credit ifrs-full:Borrowings
1091 Derivatives at end of year Concept (Monetary) As Of Debit relx:DerivativeFinancialAssetLiability
1092 At end of year Concept (Monetary) As Of Credit relx:NetBorrowings
1093 101070 - Disclosure - Acquisitions - Consideration Paid for Acquiring Assets and Liabilities (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosureAcquisitionsConsiderationPaidForAcquiringAssetsAndLiabilitiesDetail
1094 Implied Table Table

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 implied:Table
1095 Disclosure Of Business Combinations [Abstract] Abstract ifrs-full:DisclosureOfBusinessCombinationsAbstract
1096 Goodwill Concept (Monetary) As Of Debit ifrs-full:GoodwillExpectedDeductibleForTaxPurposes
1097 Intangible assets Concept (Monetary) As Of Debit ifrs-full:IdentifiableIntangibleAssetsRecognisedAsOfAcquisitionDate
1098 Property, plant and equipment Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipmentRecognisedAsOfAcquisitionDate
1099 Current assets Concept (Monetary) As Of Debit ifrs-full:CurrentAssetsRecognisedAsOfAcquisitionDate
1100 Non current assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentAssetsRecognisedAsOfAcquisitionDate
1101 Current liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentLiabilitiesRecognisedAsOfAcquisitionDate
1102 Borrowings Concept (Monetary) As Of Credit ifrs-full:BorrowingsRecognisedAsOfAcquisitionDate
1103 Deferred tax Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilitiesRecognisedAsOfAcquisitionDate
1104 Net assets acquired Concept (Monetary) As Of Debit ifrs-full:IdentifiableAssetsAcquiredLiabilitiesAssumed
1105 Consideration (after taking account of £27m (2017: £7m; 2016: £10m) net cash acquired) Concept (Monetary) As Of Credit ifrs-full:AcquisitiondateFairValueOfTotalConsiderationTransferred
1106 Less: consideration deferred to future years Concept (Monetary) As Of Credit ifrs-full:LiabilitiesIncurred
1107 Less: acquisition date fair value of equity interest Concept (Monetary) As Of Credit ifrs-full:EquityInterestsOfAcquirer
1108 Net cash flow Concept (Monetary) As Of Credit ifrs-full:CashTransferred
1109 101080 - Disclosure - Acquisitions - Consideration Paid for Acquiring Assets and Liabilities (Parenthetical) (Detail) Network

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1110 Implied Table Table

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1111 Disclosure Of Business Combinations [Abstract] Abstract ifrs-full:DisclosureOfBusinessCombinationsAbstract
1112 Cash of acquired businesses at acquisition date Concept (Monetary) As Of Debit relx:CashOfAcquiredBusinessesAtAcquisitionDate
1113 101090 - Disclosure - Acquisitions - Additional Information (Detail) Network

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*

 http://relx.com/20181231/taxonomy/role/DisclosureAcquisitionsAdditionalInformationDetail
1114 Disclosure Of Business Combinations [Table] Table

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*

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1115 Business combinations [axis] Axis ifrs-full:BusinessCombinationsAxis
1116 Entity's total for business combinations [member] Member ifrs-full:EntitysTotalForBusinessCombinationsMember
1117 ThreatMetrix [member] Member relx:ThreatMetrixMember
1118 Disclosure Of Business Combinations [Line Items] LineItems ifrs-full:DisclosureOfBusinessCombinationsLineItems
1119 Share capital acquired Concept (Percent) As Of ifrs-full:PercentageOfVotingEquityInterestsAcquired
1120 Consideration (after taking account of net cash acquired) Concept (Monetary) As Of Credit ifrs-full:AcquisitiondateFairValueOfTotalConsiderationTransferred
1121 Goodwill Concept (Monetary) As Of Debit ifrs-full:GoodwillExpectedDeductibleForTaxPurposes
1122 Intangible assets Concept (Monetary) As Of Debit ifrs-full:IdentifiableIntangibleAssetsRecognisedAsOfAcquisitionDate
1123 Acquisition relating to trade and other payables Concept (Monetary) As Of Credit ifrs-full:CurrentLiabilitiesRecognisedAsOfAcquisitionDate
1124 Net deferred tax liabilities recognised as of acquisition date Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilitiesRecognisedAsOfAcquisitionDate
1125 Revenue contributed by business acquisition Concept (Monetary) For Period Credit ifrs-full:RevenueOfAcquiree
1126 Increased adjusted operating profit Concept (Monetary) For Period Credit relx:IncreaseDecreaseInProfitLossFromOperatingActivities
1127 Decreased net profit Concept (Monetary) For Period Credit ifrs-full:ProfitLossOfAcquiree
1128 Integration costs and amortisation of acquired intangibles Concept (Monetary) For Period Debit relx:AmortisationOfAcquiredIntangiblesAssetsIntegrationCosts
1129 Net cash inflow from operating activities contributed by business acquisition Concept (Monetary) For Period Debit relx:NetCashInflowArisingFromAcquisition
1130 Group revenue, pro forma basis Concept (Monetary) For Period Credit ifrs-full:RevenueOfCombinedEntity
1131 Adjusted operating profit, pro forma basis Concept (Monetary) For Period Credit relx:AdjustedOperatingProfitOfCombinedEntity
1132 Adjusted net profit, pro forma basis Concept (Monetary) For Period Credit ifrs-full:ProfitLossOfCombinedEntity
1133 101100 - Disclosure - Equity Dividends - Ordinary Dividends Paid (Detail) Network

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*

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1134 Disclosure Of Dividends [Table] Table

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*

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1135 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
1136 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
1137 RELX PLC [member] Member relx:RELXPLCMember
1138 RELX NV [member] Member relx:RELXNVMember
1139 Disclosure of Dividends [line items] LineItems relx:DisclosureOfDividendsLineItems
1140 Ordinary dividends paid Concept (Monetary) For Period Credit ifrs-full:DividendsPaidToEquityHoldersOfParentClassifiedAsFinancingActivities
1141 101110 - Disclosure - Equity Dividends - Additional Information (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosureEquityDividendsAdditionalInformationDetail
1142 Disclosure Of Classes Of Share Capital [Table] Table

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*

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1143 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
1144 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
1145 RELX PLC [member] Member relx:RELXPLCMember
1146 RELX NV [member] Member relx:RELXNVMember
1147 Disclosure of Dividends [line items] LineItems relx:DisclosureOfDividendsLineItems
1148 Final dividend Concept (Share) For Period relx:FinalDividendsPaid
1149 Interim dividend Concept (Share) For Period relx:InterimDividendsPaid
1150 Total dividends Concept (Share) For Period ifrs-full:DividendsPaidOrdinarySharesPerShare
1151 Final dividends payment to former shareholders Concept (Share) For Period relx:FinalDividendPaymentToFormerShareholders
1152 Interim dividend payment to former shareholders Concept (Share) For Period relx:InterimDividendPaymentToFormerShareholders
1153 Final dividend proposed Concept (Share) For Period relx:FinalDividendsProposed
1154 Dividend proposed Concept (Share) For Period relx:DividendsProposed
1155 Dividend payables Concept (Monetary) As Of Credit ifrs-full:DividendPayables
1156 101120 - Disclosure - Goodwill - Summary of Changes in Goodwill (Detail) Network

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*

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1157 Implied Table Table

*

*

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1158 Disclosure Of Reconciliation Of Changes In Goodwill [Abstract] Abstract ifrs-full:DisclosureOfReconciliationOfChangesInGoodwillAbstract
1159 At start of year Concept (Monetary) As Of Debit ifrs-full:Goodwill
1160 Acquisitions Concept (Monetary) For Period Debit ifrs-full:AdditionalRecognitionGoodwill
1161 Disposals/reclassified as held for sale Concept (Monetary) For Period Credit relx:DecreaseThroughDisposalsOrClassifiedAsHeldForSaleGoodwill
1162 Transfers Concept (Monetary) For Period Debit relx:GoodwillTransferDueToFinalisationOfAcquisitions
1163 Exchange translation differences Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughNetExchangeDifferencesGoodwill
1164 At end of year Concept (Monetary) As Of Debit ifrs-full:Goodwill
1165 101130 - Disclosure - Goodwill - Additional Information (Detail) Network

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*

 http://relx.com/20181231/taxonomy/role/DisclosureGoodwillAdditionalInformationDetail
1166 Disclosure Of Information For Individual Asset Or Cashgenerating Unit With Significant Amount Of Goodwill Or Intangible Assets With Indefinite Useful Lives [Table] Table

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*

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1167 Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount [axis] Axis ifrs-full:CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis
1168 Carrying amount [member] Member ifrs-full:CarryingAmountMember
1169 Accumulated amortisation [member] Member relx:AccumulatedAmortisationMember
1170 Accumulated impairment [member] Member ifrs-full:AccumulatedImpairmentMember
1171 Disclosure of information for cash-generating units [line items] LineItems ifrs-full:DisclosureOfInformationForIndividualAssetOrCashgeneratingUnitWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesLineItems
1172 Goodwill Concept (Monetary) As Of Debit ifrs-full:Goodwill
1173 Impairment of goodwill Concept (Monetary) For Period ifrs-full:ImpairmentLossRecognisedInProfitOrLossGoodwill
1174 Nominal long-term market growth rates maximum forecast period Concept (xbrli:durationItemType) For Period relx:NominalLongtermMarketGrowthRatesMaximumForecastPeriod
1175 Increase in discount rate Concept (Percent) For Period relx:ReasonablyPossibleIncreaseInDiscountRatesAppliedToCashFlowProjections
1176 Decrease in the compound annual growth rate for cash flow Concept (Percent) For Period relx:ReasonablyPossibleDecreaseInCompoundAnnualGrowthRateForCashFlowDuringForecastPeriod
1177 Decrease in nominal long-term market growth rates Concept (Percent) For Period relx:ReasonablyPossibleDecreaseInNominalLongTermMarketGrowthRates
1178 Impairment charges result from sensitivity analysis Concept (Monetary) For Period Debit relx:EstimatedImpairmentChargesResultFromSensitivityAnalysis
1179 Description of changes in methods and assumptions used in preparing sensitivity analysis Concept (Text/String) For Period ifrs-full:DescriptionOfValuationTechniquesUsedToMeasureFairValueLessCostsOfDisposal
1180 101140 - Disclosure - Goodwill - Summary of Goodwill by Segment (Detail) Network

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*

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1181 Disclosure Of Information For Individual Asset Or Cashgenerating Unit With Significant Amount Of Goodwill Or Intangible Assets With Indefinite Useful Lives [Table] Table

*

*

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1182 Segments [axis] Axis ifrs-full:SegmentsAxis
1183 Segments [member] Member ifrs-full:SegmentsMember
1184 Scientific, Technical & Medical [member] Member relx:ScientificTechnicalAndMedicalSegmentMember
1185 Risk & Business Analytics [member] Member relx:RiskAndBusinessAnalyticsSegmentMember
1186 Legal [member] Member relx:LegalSegmentMember
1187 Exhibitions [member] Member relx:ExhibitionsSegmentMember
1188 Disclosure of information for cash-generating units [line items] LineItems ifrs-full:DisclosureOfInformationForIndividualAssetOrCashgeneratingUnitWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesLineItems
1189 Goodwill Concept (Monetary) As Of Debit ifrs-full:Goodwill
1190 101150 - Disclosure - Goodwill - Key Assumptions Used for Each Group of Cash Generating Units (Detail) Network

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*

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1191 Disclosure Of Information For Individual Asset Or Cashgenerating Unit With Significant Amount Of Goodwill Or Intangible Assets With Indefinite Useful Lives [Table] Table

*

*

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1192 Segments [axis] Axis ifrs-full:SegmentsAxis
1193 Segments [member] Member ifrs-full:SegmentsMember
1194 Scientific, Technical & Medical [member] Member relx:ScientificTechnicalAndMedicalSegmentMember
1195 Risk & Business Analytics [member] Member relx:RiskAndBusinessAnalyticsSegmentMember
1196 Legal [member] Member relx:LegalSegmentMember
1197 Exhibitions [member] Member relx:ExhibitionsSegmentMember
1198 Disclosure of information for cash-generating units [line items] LineItems ifrs-full:DisclosureOfInformationForIndividualAssetOrCashgeneratingUnitWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesLineItems
1199 Pre-tax discount rate Concept (Percent) As Of ifrs-full:DescriptionOfDiscountRatesAppliedToCashFlowProjections
1200 Nominal long-term market growth rate Concept (Percent) As Of ifrs-full:DescriptionOfGrowthRateUsedToExtrapolateCashFlowProjections
1201 101160 - Disclosure - Intangible Assets - Additional Information (Detail) Network

*

*

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1202 Disclosure Of Intangible Assets [Table] Table

*

*

 ifrs-full:DisclosureOfIntangibleAssetsTable
1203 Classes of intangible assets other than goodwill [axis] Axis ifrs-full:ClassesOfIntangibleAssetsOtherThanGoodwillAxis
1204 Intangible assets other than goodwill [member] Member ifrs-full:IntangibleAssetsOtherThanGoodwillMember
1205 Market and customer-related [member] Member relx:MarketAndCustomerRelatedMember
1206 Content, software and other [member] Member relx:ContentSoftwareAndOtherMember
1207 Internally developed intangible assets [member] Member relx:InternallyDevelopedIntangibleAssetsMember
1208 Scientific, Technical & Medical [member] Member relx:ScientificTechnicalAndMedicalMember
1209 Range [axis] Axis ifrs-full:RangeAxis
1210 Ranges [member] Member ifrs-full:RangesMember
1211 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
1212 Top of range [member] Member ifrs-full:TopOfRangeMember
1213 Departure from requirement of IFRS [axis] Axis ifrs-full:DepartureFromRequirementOfIFRSAxis
1214 Currently stated [member] Member ifrs-full:RestatedMember
1215 Acquired pre-IFRS [member] Member relx:AcquiredPreIFRSMember
1216 Disclosure of detailed information about intangible assets [line items] LineItems ifrs-full:DisclosureOfIntangibleAssetsLineItems
1217 Finite-lived intangible assets, useful life Concept (Text/String) For Period ifrs-full:UsefulLivesOrAmortisationRatesIntangibleAssetsOtherThanGoodwill
1218 Intangible assets Concept (Monetary) As Of Debit ifrs-full:IntangibleAssetsOtherThanGoodwill
1219 Intangible assets with indefinite useful lives Concept (Monetary) As Of Debit relx:IntangibleAssetWithIndefiniteUsefulLives
1220 101170 - Disclosure - Intangible Assets - Summary of Intangible Assets (Detail) Network

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*

 http://relx.com/20181231/taxonomy/role/DisclosureIntangibleAssetsSummaryOfIntangibleAssetsDetail
1221 Disclosure Of Intangible Assets [Table] Table

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*

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1222 Methods of generation [axis] Axis ifrs-full:MethodsOfGenerationAxis
1223 Methods of generation [member] Member ifrs-full:MethodsOfGenerationMember
1224 Acquired intangible assets [member] Member ifrs-full:NotInternallyGeneratedMember
1225 Internally developed intangible assets [member] Member ifrs-full:InternallyGeneratedMember
1226 Classes of intangible assets other than goodwill [axis] Axis ifrs-full:ClassesOfIntangibleAssetsOtherThanGoodwillAxis
1227 Intangible assets other than goodwill [member] Member ifrs-full:IntangibleAssetsOtherThanGoodwillMember
1228 Market and customer-related [member] Member relx:MarketAndCustomerRelatedMember
1229 Content, software and other [member] Member relx:ContentSoftwareAndOtherMember
1230 Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount [axis] Axis ifrs-full:CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis
1231 Carrying amount [member] Member ifrs-full:CarryingAmountMember
1232 Cost [member] Member ifrs-full:GrossCarryingAmountMember
1233 Accumulated amortisation [member] Member ifrs-full:AccumulatedDepreciationAndAmortisationMember
1234 Disclosure of detailed information about intangible assets [line items] LineItems ifrs-full:DisclosureOfIntangibleAssetsLineItems
1235 Intangible assets other than goodwill at beginning of period Concept (Monetary) As Of Debit ifrs-full:IntangibleAssetsOtherThanGoodwill
1236 Acquisitions Concept (Monetary) For Period Debit ifrs-full:AcquisitionsThroughBusinessCombinationsIntangibleAssetsOtherThanGoodwill
1237 Additions Concept (Monetary) For Period Debit ifrs-full:AdditionsOtherThanThroughBusinessCombinationsIntangibleAssetsOtherThanGoodwill
1238 Charge for the year Concept (Monetary) For Period ifrs-full:AmortisationIntangibleAssetsOtherThanGoodwill
1239 Disposals/reclassified as held for sale Concept (Monetary) For Period Credit relx:DecreaseThroughDisposalsOrClassifiedAsHeldForSaleIntangibleAssetsOtherThanGoodwill
1240 Transfers Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughTransfersIntangibleAssetsOtherThanGoodwill
1241 Exchange translation differences Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughNetExchangeDifferencesIntangibleAssetsOtherThanGoodwill
1242 Intangible assets other than goodwill at end of period Concept (Monetary) As Of Debit ifrs-full:IntangibleAssetsOtherThanGoodwill
1243 101180 - Disclosure - Investments - Summary of Investments (Detail) Network

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*

 http://relx.com/20181231/taxonomy/role/DisclosureInvestmentsSummaryOfInvestmentsDetail
1244 Investment [Table] Table

*

*

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1245 Classes of assets [axis] Axis ifrs-full:ClassesOfAssetsAxis
1246 Assets [member] Member ifrs-full:ClassesOfAssetsMember
1247 Investments [member] Member ifrs-full:InvestmentPropertyMember
1248 Investment [line items] LineItems invest:InvestmentLineItems
1249 Investments in joint ventures Concept (Monetary) As Of Debit ifrs-full:InvestmentsInJointVentures
1250 Available for sale investments Concept (Monetary) As Of Debit ifrs-full:FinancialAssetsAvailableforsale
1251 Venture capital investments Concept (Monetary) As Of Debit ifrs-full:FinancialAssetsAtFairValueThroughProfitOrLossClassifiedAsHeldForTrading
1252 Total Concept (Monetary) As Of Debit ifrs-full:FinancialAssets
1253 101190 - Disclosure - Investments - Summary of Analysis of Changes in Carrying Value of Investments in Joint Ventures (Detail) Network

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*

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1254 Implied Table Table

*

*

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1255 Disclosure Of Analysis Of Changes In The Carrying Value Of Investments In Joint Ventures [Abstract] Abstract relx:DisclosureOfAnalysisOfChangesInTheCarryingValueOfInvestmentsInJointVenturesAbstract
1256 At start of year Concept (Monetary) As Of Debit ifrs-full:InvestmentsInJointVentures
1257 Share of results of joint ventures Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
1258 Dividends received from joint ventures Concept (Monetary) For Period Debit ifrs-full:DividendsReceivedFromJointVenturesClassifiedAsInvestingActivities
1259 Additions Concept (Monetary) For Period Debit relx:InvestmentsInJointVenturesAdditions
1260 Exchange translation differences Concept (Monetary) For Period Debit relx:InvestmentsInJointVenturesExchangeTranslationDifferences
1261 At end of year Concept (Monetary) As Of Debit ifrs-full:InvestmentsInJointVentures
1262 101200 - Disclosure - Investments - Summary of Group's Share of Joint Ventures (Detail) Network

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*

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1263 Disclosure Of Summary Of Group Share Of Joint Ventures [Table] Table

*

*

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1264 Joint ventures [axis] Axis ifrs-full:JointVenturesAxis
1265 Entity's total for joint ventures [member] Member ifrs-full:EntitysTotalForJointVenturesMember
1266 Joint ventures [member] Member ifrs-full:JointVenturesMember
1267 Disclosure Of Summary Of Group Share Of Joint Ventures [Line Items] LineItems relx:DisclosureOfSummaryOfGroupShareOfJointVenturesLineItems
1268 Revenue Concept (Monetary) For Period Credit ifrs-full:Revenue
1269 Net profit for the year Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
1270 Total assets Concept (Monetary) As Of Debit ifrs-full:Assets
1271 Total liabilities Concept (Monetary) As Of Credit ifrs-full:Liabilities
1272 Net assets Concept (Monetary) As Of Debit ifrs-full:NetAssetsLiabilities
1273 Goodwill Concept (Monetary) As Of Debit ifrs-full:Goodwill
1274 Total Concept (Monetary) As Of Debit ifrs-full:InvestmentsInJointVentures
1275 101210 - Disclosure - Property, Plant and Equipment - Additional Information (Detail) Network

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*

 http://relx.com/20181231/taxonomy/role/DisclosurePropertyPlantAndEquipmentAdditionalInformationDetail
1276 Disclosure Of Property Plant And Equipment [Table] Table

*

*

 ifrs-full:DisclosureOfPropertyPlantAndEquipmentTable
1277 Classes of property, plant and equipment [axis] Axis ifrs-full:ClassesOfPropertyPlantAndEquipmentAxis
1278 Property, plant and equipment [member] Member ifrs-full:PropertyPlantAndEquipmentMember
1279 Freehold land [member] Member relx:FreeholdLandMember
1280 Freehold buildings [Member] Member relx:FreeholdBuildingsMember
1281 Long lease [member] Member relx:LongLeaseholdMember
1282 Leasehold improvements [member] Member ifrs-full:LeaseholdImprovementsMember
1283 Plant [member] Member relx:PlantMember
1284 Office furniture, fixtures and fittings [member] Member ifrs-full:OfficeEquipmentMember
1285 Computer systems, communication networks and equipment [member] Member ifrs-full:ComputerEquipmentMember
1286 Range [axis] Axis ifrs-full:RangeAxis
1287 Ranges [member] Member ifrs-full:RangesMember
1288 Top of range [member] Member ifrs-full:TopOfRangeMember
1289 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
1290 Disclosure of detailed information about property, plant and equipment [line items] LineItems ifrs-full:DisclosureOfPropertyPlantAndEquipmentLineItems
1291 Depreciation Concept (Monetary) For Period ifrs-full:DepreciationPropertyPlantAndEquipment
1292 Property, plant and equipment estimated useful lives Concept (Text/String) For Period ifrs-full:UsefulLivesOrDepreciationRatesPropertyPlantAndEquipment
1293 Property, plant and equipment Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipment
1294 101220 - Disclosure - Property, Plant and Equipment - Summary of Property, Plant and Equipment (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosurePropertyPlantAndEquipmentSummaryOfPropertyPlantAndEquipmentDetail
1295 Disclosure Of Property Plant And Equipment [Table] Table

*

*

 ifrs-full:DisclosureOfPropertyPlantAndEquipmentTable
1296 Classes of property, plant and equipment [axis] Axis ifrs-full:ClassesOfPropertyPlantAndEquipmentAxis
1297 Property, plant and equipment [member] Member ifrs-full:PropertyPlantAndEquipmentMember
1298 Land and buildings [member] Member ifrs-full:LandAndBuildingsMember
1299 Fixtures and fittings [member] Member ifrs-full:FixturesAndFittingsMember
1300 Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount [axis] Axis ifrs-full:CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis
1301 Carrying amount [member] Member ifrs-full:CarryingAmountMember
1302 Cost [member] Member ifrs-full:GrossCarryingAmountMember
1303 Accumulated depreciation [member] Member relx:AccumulatedDepreciationMember
1304 Disclosure of detailed information about property, plant and equipment [line items] LineItems ifrs-full:DisclosureOfPropertyPlantAndEquipmentLineItems
1305 At start of year Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipment
1306 Charge for the year Concept (Monetary) For Period ifrs-full:DepreciationPropertyPlantAndEquipment
1307 Acquisitions Concept (Monetary) For Period Debit ifrs-full:AcquisitionsThroughBusinessCombinationsPropertyPlantAndEquipment
1308 Capital expenditure Concept (Monetary) For Period Debit ifrs-full:AdditionsOtherThanThroughBusinessCombinationsPropertyPlantAndEquipment
1309 Disposals/reclassified as held for sale Concept (Monetary) For Period Credit relx:DecreaseThroughDisposalsOrClassifiedAsHeldForSalePropertyPlantAndEquipment
1310 Exchange translation differences Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughNetExchangeDifferencesPropertyPlantAndEquipment
1311 At end of year Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipment
1312 101230 - Disclosure - Financial Instruments - Liquidity Risk - Additional Information (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureFinancialInstrumentsLiquidityRiskAdditionalInformationDetail
1313 Disclosure Of Financial Instruments [Table] Table

*

*

 ifrs-full:DisclosureOfFinancialInstrumentsTable
1314 Range [axis] Axis ifrs-full:RangeAxis
1315 Ranges [member] Member ifrs-full:RangesMember
1316 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
1317 Top of range [member] Member ifrs-full:TopOfRangeMember
1318 Types of hedges [axis] Axis ifrs-full:TypesOfHedgesAxis
1319 Hedges [member] Member ifrs-full:TypesOfHedgesMember
1320 Fair value hedges [member] Member ifrs-full:FairValueHedgesMember
1321 Cash flow hedges [member] Member ifrs-full:CashFlowHedgesMember
1322 Classes of financial liabilities [axis] Axis ifrs-full:ClassesOfFinancialLiabilitiesAxis
1323 Financial liabilities, class [member] Member ifrs-full:FinancialLiabilitiesMember
1324 Derivatives not designated as hedges [member] Member relx:DerivativesNotDesignatedAsHedgesMember
1325 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
1326 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
1327 Tranche One [member] Member relx:TrancheOneMember
1328 Tranche Two [member] Member relx:TrancheTwoMember
1329 Disclosure of detailed information about financial instruments [line items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsLineItems
1330 Maximum maturity amount of short-term debt Concept (Monetary) As Of Credit relx:MaximumMaturityAmountOfShorttermDebt
1331 Minimum levels of maintained borrowing maturities Concept (xbrli:durationItemType) For Period relx:MaintainedBorrowingsMaturityDate
1332 Derivative financial liabilities Concept (Monetary) As Of Credit ifrs-full:DerivativeFinancialLiabilities
1333 Derivative instruments not designated as hedging instruments, at fair value Concept (Monetary) For Period Debit relx:DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAtFairValue
1334 Derivative financial assets Concept (Monetary) As Of Debit ifrs-full:DerivativeFinancialAssets
1335 Financial instruments designated as hedging instruments, at fair value Concept (Monetary) As Of ifrs-full:FinancialInstrumentsDesignatedAsHedgingInstrumentsAtFairValue
1336 Committed bank facility Concept (Monetary) As Of Credit relx:CommittedBankFacility
1337 Committed bank facility maturity date Concept (Year/Month) For Period relx:CommittedBankFacilityMaturityDate
1338 Committed bank facility maturity period Concept (xbrli:durationItemType) For Period relx:CommittedBankFacilityMaturityPeriod
1339 101240 - Disclosure - Financial Instruments - Summary of Remaining Contractual Maturities for Borrowings and Derivative Financial Instruments (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureFinancialInstrumentsSummaryOfRemainingContractualMaturitiesForBorrowingsAndDerivativeFinancialInstrumentsDetail
1340 Disclosure Of Financial Instruments [Table] Table

*

*

 ifrs-full:DisclosureOfFinancialInstrumentsTable
1341 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
1342 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
1343 Contractual cash flow [member] Member relx:AggregateContractualCashFlowMember
1344 Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount [axis] Axis ifrs-full:CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis
1345 Carrying amount [member] Member ifrs-full:CarryingAmountMember
1346 Carrying amount [member] Member relx:CarryingValueMember
1347 Types of interest rates [axis] Axis ifrs-full:TypesOfInterestRatesAxis
1348 Interest rate types [member] Member ifrs-full:InterestRateTypesMember
1349 Fixed rate borrowings [member] Member ifrs-full:FixedInterestRateMember
1350 Lease liabilities [member] Member ifrs-full:LeaseLiabilitiesMember
1351 Floating rate borrowings [member] Member ifrs-full:FloatingInterestRateMember
1352 Maturity [axis] Axis ifrs-full:MaturityAxis
1353 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
1354 Within 1 year [member] Member ifrs-full:NotLaterThanOneYearMember
1355 1-2 years [member] Member ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMember
1356 2-3 years [member] Member ifrs-full:LaterThanTwoYearsAndNotLaterThanThreeYearsMember
1357 3-4 years [member] Member ifrs-full:LaterThanThreeYearsAndNotLaterThanFourYearsMember
1358 4-5 years [member] Member ifrs-full:LaterThanFourYearsAndNotLaterThanFiveYearsMember
1359 More than 5 years [member] Member ifrs-full:LaterThanFiveYearsMember
1360 Classes of financial instruments [axis] Axis ifrs-full:ClassesOfFinancialInstrumentsAxis
1361 Financial instruments, class [member] Member ifrs-full:ClassesOfFinancialInstrumentsMember
1362 Interest rate derivatives [member] Member relx:InterestRateDerivativesMember
1363 Cross-currency interest rate swaps [member] Member relx:CrosscurrencyInterestRateSwapsMember
1364 Forward foreign exchange contracts [member] Member relx:ForwardForeignExchangeContractsMember
1365 Disclosure of detailed information about financial instruments [line items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsLineItems
1366 Borrowings Concept (Monetary) As Of Credit ifrs-full:Borrowings
1367 Contractual cash flow from borrowings Concept (Monetary) For Period Debit relx:ContractualCashFlowFromBorrowings
1368 Derivative financial liabilities Concept (Monetary) As Of Credit ifrs-full:DerivativeFinancialLiabilities
1369 Derivative financial assets Concept (Monetary) As Of Debit ifrs-full:DerivativeFinancialAssets
1370 Total Concept (Monetary) As Of Debit relx:FinancialAssetLiabilitiesNet
1371 101250 - Disclosure - Financial Instruments - Market Risk - Additional Information (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureFinancialInstrumentsMarketRiskAdditionalInformationDetail
1372 Disclosure Of Financial Instruments [Table] Table

*

*

 ifrs-full:DisclosureOfFinancialInstrumentsTable
1373 Types of risks [axis] Axis ifrs-full:TypesOfRisksAxis
1374 Risks [member] Member ifrs-full:TypesOfRisksMember
1375 Market risk [member] Member ifrs-full:MarketRiskMember
1376 Classes of financial instruments [axis] Axis ifrs-full:ClassesOfFinancialInstrumentsAxis
1377 Financial instruments, class [member] Member ifrs-full:ClassesOfFinancialInstrumentsMember
1378 Foreign currency exposure management [member] Member relx:ForeignCurrencyExposureManagementMember
1379 Segments [axis] Axis ifrs-full:SegmentsAxis
1380 Segments [member] Member ifrs-full:SegmentsMember
1381 Scientific, Technical & Medical subscription businesses [member] Member relx:ScientificTechnicalMedicalSubscriptionBusinessesMember
1382 Disclosure of detailed information about financial instruments [line items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsLineItems
1383 Percentage of borrowings with either fixed interest rate or fixed through the use of interest rate swaps, forward rate agreements or options Concept (Percent) For Period relx:PercentageOfBorrowingsWithFixedInterestRateOrInterestRateSwapsForwardRateAgreementsOrOptions
1384 Borrowings, interest rate basis Concept (Percent) As Of relx:PercentageOfReasonablyPossibleIncreaseDecreaseInInterestRate
1385 Decrease in net finance costs Concept (Monetary) For Period Credit relx:DecreaseInNetFinanceCostsDueToReasonablyPossibleDecreaseInInterestRate
1386 Increase in net finance costs Concept (Monetary) For Period Debit relx:IncreaseInNetFinanceCostsDueToReasonablyPossibleIncreaseInInterestRate
1387 Increase in net equity Concept (Monetary) As Of Credit relx:IncreaseInEquityDueToReasonablyPossibleDecreaseInInterestRate
1388 Decrease in net equity Concept (Monetary) As Of Debit relx:DecreaseInEquityDueToReasonablyPossibleIncreaseInInterestRate
1389 Hedging of highly predictable future cash flows Concept (xbrli:durationItemType) For Period relx:HedgingOfHighlyPredictableFutureCashFlows
1390 Assumed weakening of foreign currencies Concept (Percent) For Period relx:AssumedWeakeningOfForeignCurrencies
1391 Decrease in carrying value of net assets due to assumed weakening of foreign currencies Concept (Monetary) For Period Credit relx:DecreaseInCarryingValueOfNetAssetsDueToAssumedWeakeningOfForeignCurrencies
1392 Decrease in net borrowings Concept (Monetary) For Period Debit relx:DecreaseInNetBorrowingsDueToAssumedWeakeningOfForeignCurrencies
1393 Assumed strengthening of foreign currencies Concept (Percent) For Period relx:AssumedStrengtheningOfForeignCurrencies
1394 Increase the carrying value of net assets, excluding net borrowings Concept (Monetary) For Period Debit relx:IncreaseInCarryingValueOfNetAssetsDueToAssumedStrengtheningOfForeignCurrencies
1395 Increase net borrowings Concept (Monetary) For Period Credit relx:IncreaseInNetBorrowingsDueToAssumedStrengtheningOfForeignCurrencies
1396 Decrease in net profit Concept (Monetary) For Period Debit relx:DecreaseInNetProfitDueToAssumedWeakeningOfForeignCurrencies
1397 Increase in net profit Concept (Monetary) For Period Credit relx:IncreaseInNetProfitDueToAssumedStrengtheningOfForeignCurrencies
1398 101260 - Disclosure - Financial Instruments - Credit Risk - Additional Information (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureFinancialInstrumentsCreditRiskAdditionalInformationDetail
1399 Disclosure Of Financial Instruments [Table] Table

*

*

 ifrs-full:DisclosureOfFinancialInstrumentsTable
1400 Types of risks [axis] Axis ifrs-full:TypesOfRisksAxis
1401 Risks [member] Member ifrs-full:TypesOfRisksMember
1402 Credit risk [member] Member ifrs-full:CreditRiskMember
1403 Types of rate-regulated activities [axis] Axis ifrs-full:TypesOfRateregulatedActivitiesAxis
1404 Rate-regulated activities [member] Member ifrs-full:RateregulatedActivitiesMember
1405 Banks rated A-/A3 [member] Member relx:BanksRatedAByA3Member
1406 Past due status [axis] Axis ifrs-full:PastDueStatusAxis
1407 Past due status [member] Member ifrs-full:PastDueStatusMember
1408 Up to one month [member] Member relx:LessThanOneMonthMember
1409 Two to three months [member] Member ifrs-full:LaterThanTwoMonthsAndNotLaterThanThreeMonthsMember
1410 Four to six months [member] Member relx:LaterThanFourMonthsAndNotLaterThanSixMonthsMember
1411 Greater than six months [member] Member ifrs-full:LaterThanSixMonthsMember
1412 Disclosure of detailed information about financial instruments [line items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsLineItems
1413 Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
1414 Percentage of cash and cash equivalents held with bank". Concept (Percent) For Period relx:PercentageOfBankHeldCashAndCashEquivalents
1415 Trade receivables Concept (Monetary) As Of Debit ifrs-full:TradeReceivables
1416 101270 - Disclosure - Financial Instruments - Summary of Cash Flow Hedges (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureFinancialInstrumentsSummaryOfCashFlowHedgesDetail
1417 Disclosure Of Detailed Information About Hedged Items [Table] Table

*

*

 ifrs-full:DisclosureOfDetailedInformationAboutHedgedItemsTable
1418 Hedged items [axis] Axis ifrs-full:HedgedItemsAxis
1419 Hedged items [member] Member ifrs-full:HedgedItemsMember
1420 €550m loan notes and €550m interest rate swaps maturing 2020 [Member] Member relx:FiveFiveZeroMillionLoanNotesAndFiveFiveZeroMillionInterestRateSwapsMaturingAnd2020Member
1421 €500m bond and €500m interest rate swaps maturing 2021 [Member] Member relx:FiveFiveZeroMillionBondAndFiveFiveZeroMillionInterestRateSwapsMaturingAnd2021Member
1422 $700m bond and $700m interest rate swaps maturing 2023 [Member] Member relx:SevenZeroZeroMillionBondAndSevenZeroZeroMillionInterestRateSwapsMaturingAnd2023Member
1423 €500m bond and €500m interest rate swaps maturing 2024 [Member] Member relx:FiveZeroZeroMillionBondAndFiveZeroZeroMillionInterestRateSwapsMaturingAnd2024Member
1424 €600m bond and €600m/$669.3m cross-currency interest rate swaps maturing 2025 [Member] Member relx:SixZeroZeroMillionBondAndSixZeroZeroMillionSixSixNineThreeMillionCrossCurrencyInterestRateSwapsMaturingAnd2025Member
1425 $200m bond and $200m interest rate swaps maturing 2027 [Member] Member relx:TwoZeroZeroMillionBondAndTwoZeroZeroMillionInterestRateSwapsMaturingAnd2027Member
1426 Disclosure Of Detailed Information About Hedged Items [Line Items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutHedgedItemsLineItems
1427 Principal amount £m Concept (Monetary) As Of Debit relx:FairValueHedgePrincipleValue
1428 Fixed Rate Concept (Percent) For Period relx:FairValueHedgeFixedInterestRate
1429 Floating Rate Concept (Text/String) For Period relx:FairValueHedgeFloatingRate
1430 101280 - Disclosure - Financial Instruments - Summary of Gains and Losses on the Borrowings and Related Derivatives Designated as Fair Value Hedges (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureFinancialInstrumentsSummaryOfGainsAndLossesOnBorrowingsAndRelatedDerivativesDesignatedAsFairValueHedgesDetail
1431 Disclosure Of Detailed Information About Hedged Items [Table] Table

*

*

 ifrs-full:DisclosureOfDetailedInformationAboutHedgedItemsTable
1432 Hedged items [axis] Axis ifrs-full:HedgedItemsAxis
1433 Hedged items [member] Member ifrs-full:HedgedItemsMember
1434 USD debt [member] Member relx:UsdDebtMember
1435 USD debt Related interest rate swaps [member] Member relx:USDDebtRelatedInterestRateSwapsMember
1436 total of USD debt and Interest rate swaps [Member] Member relx:UsdDebtAndInterestRateSwapsMember
1437 GBP Debt [Member] Member relx:GBPDebtMember
1438 EUR debt [member] Member relx:EURDebtMember
1439 GBP Debt Related Interest Rate Swaps [member] Member relx:GBPDebtRelatedInterestRateSwapsMember
1440 EUR Debt related interest rate swaps [member] Member relx:EurDebtRelatedInterestRateSwapsMember
1441 Total of GBP and interest rate swaps [Member] Member relx:GBPDebtAndInterestRateSwapsMember
1442 Total of Eur debt and interest rate swaps [Member] Member relx:EURDebtAndInterestRateSwapMember
1443 Net Relating to USD, GBP, EUR And CHF Debt [Member] Member relx:NetRelatingToUSDGBPEURAndCHFDebtMember
1444 Total related interest rate swaps [member] Member relx:NetRelatedInterestRateSwapsMember
1445 Disclosure Of Detailed Information About Hedged Items [Line Items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutHedgedItemsLineItems
1446 1 January 2018 £m Concept (Monetary) As Of Debit relx:AccumulatedFairValueHedgeAdjustmentOnHedgedAssetsLiabilities
1447 Fair value movement gain/(loss) £m Concept (Monetary) For Period Credit ifrs-full:GainLossOnChangeInFairValueOfHedgedItemUsedAsBasisForRecognisingHedgeIneffectiveness
1448 Exchange gain/(loss) £m Concept (Monetary) For Period Debit relx:IncreaseDecreaseThroughNetExchangeDifferencesHedgedItems
1449 31 December 2018 £m Concept (Monetary) As Of Debit relx:AccumulatedFairValueHedgeAdjustmentOnHedgedAssetsLiabilities
1450 Carrying values £m Concept (Monetary) As Of Debit relx:AccumulatedFairValueHedgeAdjustmentOnHedgedItemIncludedInCarryingAmount
1451 De-designated £m Concept (Monetary) For Period Credit relx:GainLossOnDedesignationOfFinancialInstrumentAsMeasuredAtFairValueThroughProfitOrLoss
1452 101290 - Disclosure - Financial Instruments - Fair Value Hedges - Additional Information (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureFinancialInstrumentsFairValueHedgesAdditionalInformationDetail
1453 Disclosure Of Financial Instruments [Table] Table

*

*

 ifrs-full:DisclosureOfFinancialInstrumentsTable
1454 Hedging instruments [axis] Axis ifrs-full:HedgingInstrumentsAxis
1455 Hedging instruments [member] Member ifrs-full:HedgingInstrumentsMember
1456 Fair value hedge de-designated in 2008 [member] Member relx:FairValueHedgeDeDesignatedIn2008Member
1457 Disclosure of detailed information about financial instruments [line items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsLineItems
1458 Fair value adjustments to borrowings de-designated in a fair value hedge relationship Concept (Monetary) As Of Credit relx:FairValueAdjustmentsToBorrowingsDeDesignatedAsFairValueHedge
1459 Cash inflow from de-designation of derivatives previously held at fair value Concept (Monetary) As Of Credit relx:CashInflowFromDeDesignationOfDerivativesPreviouslyHeldAtFairValue
1460 Amortisation of fair value adjustments Concept (Monetary) As Of Debit relx:AmortisationOfFairValueAdjustments
1461 101300 - Disclosure - Financial Instruments - Cash Flow Hedges - Additional Information (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureFinancialInstrumentsCashFlowHedgesAdditionalInformationDetail
1462 Implied Table Table

*

*

 implied:Table
1463 Disclosure Of Financial Instruments [Abstract] Abstract ifrs-full:DisclosureOfFinancialInstrumentsAbstract
1464 Bonds issued Concept (Monetary) As Of Credit ifrs-full:BondsIssued
1465 Deferred tax charge (credit) in respect of hedge reserve gains (losses) Concept (Monetary) As Of Debit relx:DeferredTaxCreditsChargesFromGainsAndLossesOfCashFlowHedges
1466 Cash flow hedge gain (loss) recognised in revenue Concept (Monetary) For Period Credit relx:CashFlowHedgeGainsLossesRecognisedInRevenue
1467 Cash flow hedge gain (loss) recognised in finance costs Concept (Monetary) For Period Credit relx:CashFlowHedgeGainsLossesRecognisedInFinanceCosts
1468 Tax credits in relation to cash flow hedges Concept (Monetary) For Period Credit relx:TaxCreditsInRelationToCashFlowHedges
1469 101310 - Disclosure - Financial Instruments - Summary of Movements in the Hedge Reserve Including Gains and Losses on Cash Flow Hedging Instruments (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureFinancialInstrumentsSummaryOfMovementsInHedgeReserveIncludingGainsAndLossesOnCashFlowHedgingInstrumentsDetail
1470 Disclosure Of Financial Instruments [Table] Table

*

*

 ifrs-full:DisclosureOfFinancialInstrumentsTable
1471 Types of hedges [axis] Axis ifrs-full:TypesOfHedgesAxis
1472 Hedges [member] Member ifrs-full:TypesOfHedgesMember
1473 Interest rate hedge reserve [member] Member relx:InterestRateHedgeReserveMember
1474 Cost of hedging reserve [member] Member relx:CostOfHedgingReserveMember
1475 Foreign currency hedge reserve [member] Member relx:ForeignCurrencyHedgeReserveMember
1476 Disclosure of detailed information about financial instruments [line items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsLineItems
1477 Hedge reserve balance at the start of the period: gains/(Losses) deferred Concept (Monetary) As Of Credit ifrs-full:ReserveOfCashFlowHedges
1478 Gain (Losses) arising during the period Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnCashFlowHedgesBeforeTax
1479 Transfer to net profit from cash flow hedge reserve Concept (Monetary) For Period Debit ifrs-full:ReclassificationAdjustmentsOnCashFlowHedgesBeforeTax
1480 Exchange translation differences Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnExchangeDifferencesOnTranslationBeforeTax
1481 Hedge reserve balance at the start of the period: gains/(Losses) deferred Concept (Monetary) As Of Credit ifrs-full:ReserveOfCashFlowHedges
1482 Reclassification on 1 January 2018 Concept (Monetary) As Of Credit relx:ReclassificationAdjustmentHedgeReserve
1483 101320 - Disclosure - Financial Instruments - Summary of Deferred Gains and Losses on Cash Flow Hedges Currently Expected to Recognised in Future Period (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureFinancialInstrumentsSummaryOfDeferredGainsAndLossesOnCashFlowHedgesCurrentlyExpectedToRecognisedInFuturePeriodDetail
1484 Disclosure Of Financial Instruments [Table] Table

*

*

 ifrs-full:DisclosureOfFinancialInstrumentsTable
1485 Maturity [axis] Axis ifrs-full:MaturityAxis
1486 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
1487 2019 Member ifrs-full:NotLaterThanOneYearMember
1488 2020 Member ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMember
1489 2021 Member ifrs-full:LaterThanTwoYearsAndNotLaterThanThreeYearsMember
1490 2022 Member ifrs-full:LaterThanThreeYearsAndNotLaterThanFourYearsMember
1491 Types of hedges [axis] Axis ifrs-full:TypesOfHedgesAxis
1492 Hedges [member] Member ifrs-full:TypesOfHedgesMember
1493 Foreign currency hedge reserve [member] Member relx:ForeignCurrencyHedgeReserveMember
1494 Principal Amount of Hedges [Member] Member relx:PrincipalAmountOfHedgesMember
1495 Disclosure of detailed information about financial instruments [line items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsLineItems
1496 Gains/(losses) deferred in hedge reserve Concept (Monetary) As Of Credit ifrs-full:ReserveOfCashFlowHedges
1497 101330 - Disclosure - Inventories and Pre-publication Costs - Summary of Inventories and Pre-Publication Costs (Detail) Network

*

*

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1498 Implied Table Table

*

*

 implied:Table
1499 Disclosure Of Information About Inventories Explanatory [Abstract] Abstract relx:DisclosureOfInformationAboutInventoriesExplanatoryAbstract
1500 Raw materials Concept (Monetary) As Of Debit ifrs-full:RawMaterials
1501 Pre-publication costs Concept (Monetary) As Of Debit relx:PrepublicationCosts
1502 Finished goods Concept (Monetary) As Of Debit ifrs-full:FinishedGoods
1503 Total Concept (Monetary) As Of Debit relx:InventoriesAndPrepublicationCosts
1504 101340 - Disclosure - Trade and Other Receivables - Summary of Trade and Other Receivables (Detail) Network

*

*

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1505 Implied Table Table

*

*

 implied:Table
1506 Trade And Other Receivables [Abstract] Abstract ifrs-full:TradeAndOtherReceivablesAbstract
1507 Trade receivables Concept (Monetary) As Of Debit ifrs-full:TradeReceivables
1508 Loss allowance Concept (Monetary) As Of Credit ifrs-full:AllowanceAccountForCreditLossesOfFinancialAssets
1509 Trade receivables before prepayments and accrued income Concept (Monetary) As Of Debit relx:TradeReceivablesBeforePrepaymentsAndAccruedIncome
1510 Prepayments and accrued income Concept (Monetary) As Of Debit ifrs-full:PrepaymentsAndAccruedIncome
1511 Net finance lease receivable Concept (Monetary) As Of Debit ifrs-full:FinanceLeaseReceivables
1512 Total Concept (Monetary) As Of Debit ifrs-full:TradeAndOtherReceivables
1513 101350 - Disclosure - Trade and Other Receivables - Summary of Movements in Loss Allowance for Expected Credit Losses (Detail) Network

*

*

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1514 Implied Table Table

*

*

 implied:Table
1515 Trade And Other Receivables [Abstract] Abstract ifrs-full:TradeAndOtherReceivablesAbstract
1516 At start of year Concept (Monetary) As Of Credit ifrs-full:AllowanceAccountForCreditLossesOfFinancialAssets
1517 Charge for the year Concept (Monetary) For Period Debit ifrs-full:ImpairmentLossRecognisedInProfitOrLossTradeReceivables
1518 Trade receivables written off Concept (Monetary) For Period Debit ifrs-full:UtilisationAllowanceAccountForCreditLossesOfFinancialAssets
1519 Exchange translation differences Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughNetExchangeDifferencesAllowanceAccountForCreditLossesOfFinancialAssets
1520 At end of year Concept (Monetary) As Of Credit ifrs-full:AllowanceAccountForCreditLossesOfFinancialAssets
1521 101360 - Disclosure - Trade and Other Payables - Summary of Trade and Other Payables (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureTradeAndOtherPayablesSummaryOfTradeAndOtherPayablesDetail
1522 Implied Table Table

*

*

 implied:Table
1523 Trade And Other Payables [Abstract] Abstract ifrs-full:TradeAndOtherPayablesAbstract
1524 Trade payables Concept (Monetary) As Of Credit ifrs-full:TradeAndOtherCurrentPayablesToTradeSuppliers
1525 Accruals Concept (Monetary) As Of Credit ifrs-full:AccrualsClassifiedAsCurrent
1526 Social security and other taxes Concept (Monetary) As Of Credit ifrs-full:CurrentPayablesOnSocialSecurityAndTaxesOtherThanIncomeTax
1527 Other payables Concept (Monetary) As Of Credit ifrs-full:OtherCurrentPayables
1528 Deferred income Concept (Monetary) As Of Credit ifrs-full:DeferredIncomeClassifiedAsCurrent
1529 Total Concept (Monetary) As Of Credit ifrs-full:TradeAndOtherCurrentPayables
1530 101370 - Disclosure - Borrowings - Summary of types of Borrowings both Current and Non-current (Detail) Network

*

*

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1531 Disclosure Of Detailed Information About Borrowings [Table] Table

*

*

 ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsTable
1532 Maturity [axis] Axis ifrs-full:MaturityAxis
1533 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
1534 Within 1 year [member] Member ifrs-full:NotLaterThanOneYearMember
1535 More than 1 year [member] Member ifrs-full:LaterThanOneYearMember
1536 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
1537 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
1538 Short-term bank loans, overdrafts and commercial paper [member] Member relx:ShortTermBankLoansOverdraftsAndCommercialPaperMember
1539 Term debt, excluding fair value hedging relationships [member] Member relx:TermDebtExcludingFairValueHedgingRelationshipsMember
1540 Lease liabilities [member] Member ifrs-full:LeaseLiabilitiesMember
1541 Term debt, in fair value hedging relationships [member] Member relx:TermDebtInFairValueHedgingRelationshipsMember
1542 Term debt, previously in fair value hedging relationships [member] Member relx:TermDebtPreviouslyInFairValueHedgingRelationshipsMember
1543 Disclosure of detailed information about borrowings [line items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
1544 Total Concept (Monetary) As Of Credit ifrs-full:Borrowings
1545 101380 - Disclosure - Borrowings - Additional Information (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureBorrowingsAdditionalInformationDetail
1546 Disclosure Of Detailed Information About Borrowings [Table] Table

*

*

 ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsTable
1547 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
1548 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
1549 Term debt, in fair value hedging relationships [member] Member relx:TermDebtInFairValueHedgingRelationshipsMember
1550 Term debt, previously in fair value hedging relationships [member] Member relx:TermDebtPreviouslyInFairValueHedgingRelationshipsMember
1551 Tranche One [member] Member relx:TrancheOneMember
1552 Tranche Two [member] Member relx:TrancheTwoMember
1553 Disclosure of detailed information about borrowings [line items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
1554 Total fair value of financial liabilities measured at amortised cost (excluding lease liabilities) Concept (Monetary) As Of Credit ifrs-full:FinancialLiabilitiesAtAmortisedCost
1555 Total fair value of term debt Concept (Monetary) As Of Credit ifrs-full:FinancialLiabilitiesAtFairValue
1556 Percentage ownership of a subsidiary Concept (Percent) For Period ifrs-full:ProportionOfOwnershipInterestInSubsidiary
1557 Committed bank facility Concept (Monetary) As Of Credit relx:CommittedBankFacility
1558 Committed bank facility maturity date Concept (Year/Month) For Period relx:CommittedBankFacilityMaturityDate
1559 Term debt Concept (Monetary) As Of Credit relx:DerivativeFinancialInstrumentsTermDebt
1560 Fair value of derivative financial instruments Concept (Monetary) For Period Debit relx:FairValueOfDerivativeFinancialInstruments
1561 101390 - Disclosure - Borrowings - Summary of Repayment Years for Borrowings (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureBorrowingsSummaryOfRepaymentYearsForBorrowingsDetail
1562 Disclosure Of Detailed Information About Borrowings [Table] Table

*

*

 ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsTable
1563 Maturity [axis] Axis ifrs-full:MaturityAxis
1564 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
1565 Within 1 year [member] Member ifrs-full:NotLaterThanOneYearMember
1566 1-2 years [member] Member ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMember
1567 2-3 years [member] Member ifrs-full:LaterThanTwoYearsAndNotLaterThanThreeYearsMember
1568 3-4 years [member] Member ifrs-full:LaterThanThreeYearsAndNotLaterThanFourYearsMember
1569 4-5 years [member] Member ifrs-full:LaterThanFourYearsAndNotLaterThanFiveYearsMember
1570 More than 5 years [member] Member ifrs-full:LaterThanFiveYearsMember
1571 More than 1 year [member] Member ifrs-full:LaterThanOneYearMember
1572 Disclosure of detailed information about borrowings [line items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
1573 Short-term bank loans, overdrafts and commercial paper Concept (Monetary) As Of Credit ifrs-full:ShorttermBorrowings
1574 Term debt Concept (Monetary) As Of Credit relx:TermDebt
1575 Lease liabilities Concept (Monetary) As Of Credit ifrs-full:FinanceLeaseLiabilities
1576 Total Concept (Monetary) As Of Credit ifrs-full:Borrowings
1577 101400 - Disclosure - Borrowings - Analysis of Borrowings by Currency (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureBorrowingsAnalysisOfBorrowingsByCurrencyDetail
1578 Disclosure Of Detailed Information About Borrowings [Table] Table

*

*

 ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsTable
1579 Currency Axis srt:CurrencyAxis
1580 All Currencies Member currency:AllCurrenciesDomain
1581 US dollars [member] Member currency:USD
1582 Pounds Sterling [member] Member currency:GBP
1583 Euro [member] Member currency:EUR
1584 Other Currencies [member] Member relx:OtherCurrenciesMember
1585 Disclosure of detailed information about borrowings [line items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
1586 Short-term bank loans, overdrafts and commercial paper Concept (Monetary) As Of Credit ifrs-full:ShorttermBorrowings
1587 Term debt Concept (Monetary) As Of Credit relx:TermDebt
1588 Lease liabilities Concept (Monetary) As Of Credit ifrs-full:FinanceLeaseLiabilities
1589 Total Concept (Monetary) As Of Credit ifrs-full:Borrowings
1590 101410 - Disclosure - Lease arrangements - Summary of right of use assets (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureLeaseArrangementsSummaryOfRightOfUseAssetsDetail
1591 Disclosure Of Finance Lease And Operating Lease By Lessee [Table] Table

*

*

 ifrs-full:DisclosureOfFinanceLeaseAndOperatingLeaseByLesseeTable
1592 Classes of assets [axis] Axis ifrs-full:ClassesOfAssetsAxis
1593 Assets [member] Member ifrs-full:ClassesOfAssetsMember
1594 Property [member[ Member relx:PropertyMember
1595 Non-property [member] Member relx:NonPropertyMember
1596 Disclosure Of Finance Lease And Operating Lease By Lessee [Line Items] LineItems ifrs-full:DisclosureOfFinanceLeaseAndOperatingLeaseByLesseeLineItems
1597 At start of year Concept (Monetary) As Of Debit relx:RightofuseAssets1
1598 Additions Concept (Monetary) For Period Debit ifrs-full:AdditionsToRightofuseAssets
1599 Acquisitions Concept (Monetary) For Period Debit relx:AcquisitionsToRightOfUseAssets
1600 Remeasurement Concept (Monetary) For Period Debit relx:RemeasurementToRightOfUseAssets
1601 Disposals Concept (Monetary) For Period Debit relx:DisposalsToRightOfUseAssets
1602 Depreciation Concept (Monetary) For Period ifrs-full:DepreciationRightofuseAssets
1603 Exchange translation differences Concept (Monetary) For Period Debit ifrs-full:ReclassificationAdjustmentsOnExchangeDifferencesOnTranslationNetOfTax
1604 At end of year Concept (Monetary) As Of Debit relx:RightofuseAssets1
1605 101420 - Disclosure - Lease arrangements - Summary of Lease liability (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureLeaseArrangementsSummaryOfLeaseLiabilityDetail
1606 Disclosure Of Finance Lease And Operating Lease By Lessee [Table] Table

*

*

 ifrs-full:DisclosureOfFinanceLeaseAndOperatingLeaseByLesseeTable
1607 Classes of assets [axis] Axis ifrs-full:ClassesOfAssetsAxis
1608 Assets [member] Member ifrs-full:ClassesOfAssetsMember
1609 Property [member[ Member relx:PropertyMember
1610 Non-property [member] Member relx:NonPropertyMember
1611 Disclosure Of Finance Lease And Operating Lease By Lessee [Line Items] LineItems ifrs-full:DisclosureOfFinanceLeaseAndOperatingLeaseByLesseeLineItems
1612 Current lease liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentLeaseLiabilities
1613 Non-current lease liabilities Concept (Monetary) As Of Credit ifrs-full:NoncurrentLeaseLiabilities
1614 Total lease liabilities Concept (Monetary) As Of Credit ifrs-full:LeaseLiabilities
1615 101430 - Disclosure - Lease Arrangements - Additional Information (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureLeaseArrangementsAdditionalInformationDetail
1616 Implied Table Table

*

*

 implied:Table
1617 Presentation Of Leases For Lessee [Abstract] Abstract ifrs-full:PresentationOfLeasesForLesseeAbstract
1618 Interest expense on lease liabilities Concept (Monetary) For Period Debit ifrs-full:InterestExpenseOnLeaseLiabilities
1619 Leases with future cash outflows Concept (Monetary) For Period Debit ifrs-full:ExpenseRelatingToVariableLeasePaymentsNotIncludedInMeasurementOfLeaseLiabilities
1620 101440 - Disclosure - Lease Arrangements - Summary of Right of Use Asset (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureLeaseArrangementsSummaryOfRightOfUseAssetDetail
1621 Implied Table Table

*

*

 implied:Table
1622 Disclosure Of Finance Lease And Operating Lease By Lessee [Abstract] Abstract ifrs-full:DisclosureOfFinanceLeaseAndOperatingLeaseByLesseeAbstract
1623 Net finance lease receivable Concept (Monetary) As Of Debit relx:DiscountedFinanceLeasePaymentsToBeReceived
1624 101450 - Disclosure - Provisions - Summary of Changes in Provisions (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureProvisionsSummaryOfChangesInProvisionsDetail
1625 Implied Table Table

*

*

 implied:Table
1626 Disclosure Of Other Provisions [Abstract] Abstract ifrs-full:DisclosureOfOtherProvisionsAbstract
1627 At start of year Concept (Monetary) As Of Credit ifrs-full:OtherProvisions
1628 Utilised Concept (Monetary) For Period Debit ifrs-full:ProvisionUsedOtherProvisions
1629 Exchange translation differences Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughNetExchangeDifferencesOtherProvisions
1630 Total Concept (Monetary) As Of Credit ifrs-full:OtherProvisions
1631 101460 - Disclosure - Provisions - Summary of Provisions Included Within Current and Non-current Liabilities (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureProvisionsSummaryOfProvisionsIncludedWithinCurrentAndNonCurrentLiabilitiesDetail
1632 Implied Table Table

*

*

 implied:Table
1633 Disclosure Of Other Provisions [Abstract] Abstract ifrs-full:DisclosureOfOtherProvisionsAbstract
1634 Current liabilities Concept (Monetary) As Of Credit ifrs-full:OtherShorttermProvisions
1635 Non-current liabilities Concept (Monetary) As Of Credit ifrs-full:OtherLongtermProvisions
1636 Total Concept (Monetary) As Of Credit ifrs-full:OtherProvisions
1637 101470 - Disclosure - Share Capital, Share Premium and Shares Held in Treasury - Summary of Called up Share Capital Issued and Fully Paid (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureShareCapitalSharePremiumAndSharesHeldInTreasurySummaryOfCalledUpShareCapitalIssuedAndFullyPaidDetail
1638 Disclosure Of Classes Of Share Capital [Table] Table

*

*

 ifrs-full:DisclosureOfClassesOfShareCapitalTable
1639 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
1640 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
1641 RELX PLC [member] Member relx:RELXPLCMember
1642 RELX NV [member] Member relx:RELXNVMember
1643 Disclosure of classes of share capital [line items] LineItems ifrs-full:DisclosureOfClassesOfShareCapitalLineItems
1644 At start of year Concept (Shares) As Of ifrs-full:NumberOfSharesOutstanding
1645 Issue of ordinary shares Concept (Shares) For Period relx:IssueOfOrdinaryShares
1646 Issue of ordinary shares in exchange for RELX NV shares Concept (Shares) For Period relx:IssueOfOrdinarySharesInExchangeForRelatedPartyShares
1647 Cancellation of shares Concept (Shares) For Period relx:NumberOfCancellationOfShares
1648 At end of year Concept (Shares) As Of ifrs-full:NumberOfSharesOutstanding
1649 At start of year Concept (Monetary) As Of Credit ifrs-full:IssuedCapital
1650 Issue of ordinary shares in exchange for RELX NV shares Concept (Monetary) For Period Credit relx:IssueOfOrdinarySharesInExchangeForRelatedPartySharesValue
1651 Cancellation of shares Concept (Monetary) For Period Debit ifrs-full:ReductionOfIssuedCapital
1652 At end of year Concept (Monetary) As Of Credit ifrs-full:IssuedCapital
1653 Cancellation of ordinary shares on completion of the corporate simplification Concept (Shares) For Period relx:CancellationOfOrdinaryShares
1654 Cancellation of treasury shares on completion of the corporate simplification Concept (Shares) For Period relx:CancellationOfTreasurySharesStock
1655 Cancellation of ordinary shares on completion of the corporate simplification Concept (Monetary) For Period Debit relx:CancellationOfOrdinarySharesValue
1656 Cancellation of treasury shares on completion of the corporate simplification Concept (Monetary) For Period Debit relx:CancellationOfTreasurySharesStockValue
1657 101480 - Disclosure - Share Capital, Share Premium and Shares Held in Treasury - Summary of Number of Ordinary Shares (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureShareCapitalSharePremiumAndSharesHeldInTreasurySummaryOfNumberOfOrdinarySharesDetail
1658 Disclosure Of Classes Of Share Capital [Table] Table

*

*

 ifrs-full:DisclosureOfClassesOfShareCapitalTable
1659 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
1660 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
1661 RELX PLC [member] Member relx:RELXPLCMember
1662 RELX NV [member] Member relx:RELXNVMember
1663 Components of equity [axis] Axis ifrs-full:ComponentsOfEquityAxis
1664 Equity [member] Member ifrs-full:EquityMember
1665 Shares held in treasury [member] Member ifrs-full:TreasurySharesMember
1666 Share capital [member] Member ifrs-full:IssuedCapitalMember
1667 Disclosure of classes of share capital [line items] LineItems ifrs-full:DisclosureOfClassesOfShareCapitalLineItems
1668 At start of year Concept (Shares) As Of relx:NumberOfSharesOutstanding1
1669 At start of period Concept (Shares) As Of relx:NumberOfSharesNetOfTreasuryShares
1670 Issue of ordinary shares Concept (Shares) For Period relx:IssueOfOrdinaryShares
1671 Issue of ordinary shares in exchange for RELX NV shares Concept (Shares) For Period relx:IssueOfOrdinarySharesInExchangeForRelatedPartyShares
1672 Repurchase of ordinary shares Concept (Shares) For Period relx:NumberOfRepurchaseOfOrdinaryShares
1673 Net (purchase)/release of shares by the Employee Benefit Trust Concept (Shares) As Of relx:PurchaseReleaseOfSharesByEmployeeBenefitTrust
1674 Cancellation of shares Concept (Shares) For Period relx:NumberOfCancellationOfShares
1675 At end of year Concept (Shares) As Of relx:NumberOfSharesOutstanding1
1676 Net release of shares by the Employee Benefit Trust Concept (Shares) For Period relx:NumberOfNetReleaseOfSharesByEmployeeBenefitTrust
1677 Cancellation of ordinary shares on completion of the corporate simplification Concept (Shares) For Period relx:CancellationOfOrdinaryShares
1678 Cancellation of treasury shares on completion of the corporate simplification Concept (Shares) For Period relx:CancellationOfTreasurySharesStock
1679 At start of period, treasury shares Concept (Shares) As Of relx:NumberOfTreasuryShares
1680 Issue of treasury shares Concept (Shares) For Period relx:NumberOfTreasurySharesIssued
1681 Issue of ordinary shares in exchange for RELX NV shares Concept (Shares) For Period relx:NumberOfTreasurySharesPurchasedFromIssueOfOrdinarySharesInExchangeForRelatedPartyShares
1682 Repurchase of ordinary shares Concept (Shares) For Period relx:NumberOfOrdinarySharesRepurchased
1683 Cancellation of treasury shares Concept (Shares) For Period relx:NumberOfTreasurySharesCancelled
1684 At end of year, treasury shares Concept (Shares) As Of relx:NumberOfTreasuryShares
1685 Net release of shares by the Employee Benefit Trust Concept (Shares) For Period relx:ReleaseOfSharesByEmployeeBenefitTrust
1686 Cancellation of ordinary shares on completion of the corporate simplification Concept (Shares) For Period relx:CancellationOfOrdinaryShares
1687 Cancellation of treasury shares on completion of the corporate simplification Concept (Shares) For Period relx:CancellationOfTreasurySharesStock
1688 Issue of ordinary shares in exchange for RELX NV shares Concept (Shares) For Period relx:OrdinarySharesIssuedInExchangeForRelatedPartySharesNetOfTreasury
1689 At end of year Concept (Shares) As Of relx:NumberOfSharesNetOfTreasuryShares
1690 101490 - Disclosure - Share Capital, Share Premium and Shares Held in Treasury - Additional Information (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureShareCapitalSharePremiumAndSharesHeldInTreasuryAdditionalInformationDetail
1691 Disclosure Of Classes Of Share Capital [Table] Table

*

*

 ifrs-full:DisclosureOfClassesOfShareCapitalTable
1692 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
1693 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
1694 RELX PLC [member] Member relx:RELXPLCMember
1695 RELX NV [member] Member relx:RELXNVMember
1696 Non-adjusting events after reporting period [axis] Axis ifrs-full:NonadjustingEventsAfterReportingPeriodAxis
1697 Non-adjusting events after reporting period [member] Member ifrs-full:NonadjustingEventsMember
1698 Ordinary Share Purchase [member] Member ifrs-full:PotentialOrdinaryShareTransactionsMember
1699 Disclosure of classes of share capital [line items] LineItems ifrs-full:DisclosureOfClassesOfShareCapitalLineItems
1700 Repurchase of ordinary shares Concept (Shares) For Period relx:NumberOfOrdinarySharesRepurchased
1701 Average price paid per share repurchased Concept (Share) For Period relx:SharesRepurchasedAveragePricePerShare
1702 Cancellation of treasury shares Concept (Shares) For Period relx:NumberOfTreasurySharesCancelled
1703 Consideration amount for repurchases of shares Concept (Monetary) For Period Credit ifrs-full:PaymentsToAcquireOrRedeemEntitysShares
1704 Employee benefit trust shares purchased Concept (Shares) For Period relx:EmployeeBenefitTrustSharesPurchased
1705 Consideration amount for employee benefit trust shares purchased Concept (Monetary) For Period Credit relx:PaymentsForPurchaseOfEmployeeBenefitTrustSharesClassifiedAsFinancingActivities
1706 Employee benefit trust shares purchase amount Concept (Monetary) As Of Debit relx:EmployeeBenefitTrustShareAtCostAmount
1707 Shares held by the employee benefit trust Concept (Shares) As Of relx:EmployeeBenefitTrustShare
1708 Shares held in treasury Concept (Shares) As Of relx:NumberOfTreasurySharesHeld
1709 Cancellation of treasury shares Concept (Shares) For Period relx:NumberOfCancellationOfShares
1710 Non-discretionary share repurchase commitment Concept (Monetary) For Period Credit relx:NonDiscretionaryShareRepurchaseCommitment
1711 Authorised amount for Share repurchase Concept (Monetary) For Period Credit relx:RepurchasesOfSharesAuthorisedAmount
1712 101500 - Disclosure - Other Reserves - Summary of Other Reserves (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureOtherReservesSummaryOfOtherReservesDetail
1713 Disclosure Of Other Reserves [Table] Table

*

*

 relx:DisclosureOfOtherReservesTable
1714 Components of equity [axis] Axis ifrs-full:ComponentsOfEquityAxis
1715 Equity [member] Member ifrs-full:EquityMember
1716 Hedge reserve [member] Member relx:HedgeReserveMember
1717 Other Reserves [member] Member ifrs-full:MiscellaneousOtherReservesMember
1718 Other reserves [member] Member ifrs-full:OtherReservesMember
1719 Disclosure of other reserves [line items] LineItems relx:DisclosureOfOtherReservesLineItems
1720 Other reserves, at start of year Concept (Monetary) As Of Credit ifrs-full:OtherReserves
1721 RELX PLC shareholders Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToOwnersOfParent
1722 Dividends paid Concept (Monetary) For Period Debit ifrs-full:DividendsPaid
1723 Actuarial (losses)/gains on defined benefit pension schemes Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans
1724 Fair value movements on cash flow hedges Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnCashFlowHedgesBeforeTax
1725 Transfer to net profit from cash flow hedge reserve Concept (Monetary) For Period Debit ifrs-full:ReclassificationAdjustmentsOnCashFlowHedgesBeforeTax
1726 Tax recognised in other comprehensive income Concept (Monetary) For Period ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncome
1727 Increase in share based remuneration reserve (net of tax) Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughSharebasedPaymentTransactions
1728 Issue of ordinary shares, net of expenses Concept (Monetary) For Period Credit ifrs-full:IssueOfEquity
1729 Cancellation of shares Concept (Monetary) For Period Credit ifrs-full:CancellationOfTreasuryShares
1730 Settlement of share awards Concept (Monetary) For Period Credit relx:IncreaseDecreaseThroughSettlementOfShareAwards
1731 Exchange translation differences Concept (Monetary) For Period Credit relx:IncreaseDecreaseThroughNetExchangeDifferencesOtherReserves
1732 Other reserves, at end of year Concept (Monetary) As Of Credit ifrs-full:OtherReserves
1733 101510 - Disclosure - Related Party Transactions - Additional Information (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureRelatedPartyTransactionsAdditionalInformationDetail
1734 Disclosure Of Transactions Between Related Parties [Table] Table

*

*

 ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesTable
1735 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
1736 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
1737 Joint ventures where entity is venturer [member] Member ifrs-full:JointVenturesWhereEntityIsVenturerMember
1738 Disclosure of transactions between related parties [line items] LineItems ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesLineItems
1739 Revenue from sale of goods, related party transactions Concept (Monetary) For Period Credit ifrs-full:RevenueFromSaleOfGoodsRelatedPartyTransactions
1740 Revenue from rendering of services, related party transactions Concept (Monetary) For Period Credit ifrs-full:RevenueFromRenderingOfServicesRelatedPartyTransactions
1741 Amounts receivable, related party transactions Concept (Monetary) As Of Debit ifrs-full:AmountsReceivableRelatedPartyTransactions
1742 Amounts payable, related party transactions Concept (Monetary) As Of Credit ifrs-full:AmountsPayableRelatedPartyTransactions
1743 Deemed benefits provided to Non-executive directors Concept (Monetary) For Period Debit relx:NonExecutiveDirectorsDeemedBenefits
1744 Loans, advances or guarantees on behalf of directors Concept (Monetary) As Of Debit relx:LoansAdvancesOrGuaranteesBehalfOfDirectors
1745 Aggregate gains made by executive directors Concept (Monetary) For Period Debit relx:GainsMadeByExecutiveDirectorsOnExerciseOfOptions
1746 101520 - Disclosure - Related Party Transactions - Summary of Key Management Personnel Remuneration (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureRelatedPartyTransactionsSummaryOfKeyManagementPersonnelRemunerationDetail
1747 Implied Table Table

*

*

 implied:Table
1748 Disclosure Of Transactions Between Related Parties [Abstract] Abstract ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesAbstract
1749 Salaries, other short-term employee benefits and non-executive fees Concept (Monetary) For Period Debit ifrs-full:KeyManagementPersonnelCompensationShorttermEmployeeBenefits
1750 Post-employment benefits Concept (Monetary) For Period Debit ifrs-full:KeyManagementPersonnelCompensationPostemploymentBenefits
1751 Share based remuneration Concept (Monetary) For Period Debit ifrs-full:KeyManagementPersonnelCompensationSharebasedPayment
1752 Total Concept (Monetary) For Period Debit ifrs-full:KeyManagementPersonnelCompensation
1753 101530 - Disclosure - Related Party Transactions - Summary of Executive Directors Remuneration (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureRelatedPartyTransactionsSummaryOfExecutiveDirectorsRemunerationDetail
1754 Implied Table Table

*

*

 implied:Table
1755 Disclosure Of Transactions Between Related Parties [Abstract] Abstract ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesAbstract
1756 Executive directors salary Concept (Monetary) For Period Debit relx:ExecutiveDirectorsSalary
1757 Executive directors benefits Concept (Monetary) For Period Debit relx:ExecutiveDirectorsBenefits
1758 Executive directors annual incentive Concept (Monetary) For Period Debit relx:ExecutiveDirectorsAnnualIncentive
1759 Executive directors cost of share based remuneration Concept (Monetary) For Period Debit relx:ExecutiveDirectorsCostOfShareBasedRemuneration
1760 Executive directors cost of pension provision Concept (Monetary) For Period Debit relx:ExecutiveDirectorsCostOfPensionProvision
1761 Total executive directors Concept (Monetary) For Period Debit relx:ExecutiveDirectors
1762 101540 - Disclosure - Related Party Transactions - Summary of Non-Executive Directors Remuneration (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureRelatedPartyTransactionsSummaryOfNonExecutiveDirectorsRemunerationDetail
1763 Implied Table Table

*

*

 implied:Table
1764 Disclosure Of Transactions Between Related Parties [Abstract] Abstract ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesAbstract
1765 Fees and benefits Concept (Monetary) For Period Debit relx:NonExecutiveDirectorsFeesAndBenefits
1766 101550 - Disclosure - Exchange Rates - Summary of Exchange Rates in Preparing Consolidated Statements (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureExchangeRatesSummaryOfExchangeRatesInPreparingConsolidatedStatementsDetail
1767 Disclosure Of Foreign Exchange Rates [Table] Table

*

*

 relx:DisclosureOfForeignExchangeRatesTable
1768 Currency Axis srt:CurrencyAxis
1769 All Currencies Member currency:AllCurrenciesDomain
1770 Euro to sterling [member] Member relx:EuroToSterlingMember
1771 US dollars to sterling [member] Member relx:UsDollarsToSterlingMember
1772 Consolidated and separate financial statements [axis] Axis ifrs-full:ConsolidatedAndSeparateFinancialStatementsAxis
1773 Consolidated [member] Member ifrs-full:ConsolidatedMember
1774 Income statement [member] Member relx:IncomeStatementMember
1775 Statement of financial position [member] Member relx:BalanceSheetMember
1776 Disclosure Of Foreign Exchange Rates [Line Items] LineItems relx:DisclosureOfForeignExchangeRatesLineItems
1777 Average foreign exchange rate Concept (Decimal) For Period ifrs-full:AverageForeignExchangeRate
1778 Closing foreign exchange rate Concept (Decimal) As Of ifrs-full:ClosingForeignExchangeRate
1779 101560 - Disclosure - Related undertakings - Summary of Full list of Related Parties - Australia to Italy (Detail) Network

*

*

 http://relx.com/20181231/taxonomy/role/DisclosureRelatedUndertakingsSummaryOfFullListOfRelatedPartiesAustraliaToItalyDetail
1780 Disclosure Of Transactions Between Related Parties [Table] Table

*

*

 ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesTable
1781 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
1782 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
1783 Australia [member] Member country:AU
1784 CANADA Member country:CA
1785 Austria [member] Member relx:AustriaMember
1786 Belgium [member] Member country:BE
1787 BRAZIL Member country:BR
1788 China [member] Member country:CN
1789 France [member] Member country:FR
1790 Germany [member] Member country:DE
1791 Colombia [member] Member country:CO
1792 Egypt [member] Member country:EG
1793 INDIA Member country:IN
1794 Indonesia [member] Member country:ID
1795 Ireland [member] Member country:IE
1796 Israel [member] Member country:IL
1797 Italy [member] Member country:IT
1798 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
1799 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
1800 Adaptris Pty Ltd [member] Member relx:AdaptrisPtyLtdMember
1801 ELsevier (Australia) Pty Ltd [member] Member relx:ElsevierAustraliaPtyLtdMember
1802 Fair Events Pty Ltd [member] Member relx:FairEventsPtyLtdMember
1803 Fitness Show Pty Ltd [member] Member relx:FitnessShowPtyLtdMember
1804 Reed Business Information (Australia) Pty Ltd [member] Member relx:ReedBusinessInformationAustraliaPtyLtdMember
1805 R E L X Canada Ltd Member relx:RELXCanadaLtdMember
1806 SST Software Australia Pty Ltd [member] Member relx:SSTSoftwareAustraliaPtyLtdMember
1807 Reed Exhibitions Australia Pty Ltd [member] Member relx:ReedExhibitionsAustraliaPtyLimitedMember
1808 Symbiotic Technologies Pty Ltd [member] Member relx:SymbioticTechnologiesPtyLtdMember
1809 Reed International Books Australia Pty Ltd [member] Member relx:ReedInternationalBooksAustraliaPtyLtdMember
1810 Symbiotic Technologies Operation Pty Ltd [member] Member relx:SymbioticTechnologiesOperationPtyLtdMember
1811 Reed Oz Comic-Con Pty Ltd [member] Member relx:ReedOzComicconPtyLtdMember
1812 Threat Metrix Pty Ltd [member] Member relx:ThreatMetrixPtyLtdMember
1813 RELX Australia Pty Limited [member] Member relx:RELXAustraliaPtyLimitedMember
1814 Expoxx Messebau GmbH [member] Member relx:ExpoxxMessebauGmbHMember
1815 LexisNexis Verlag ARD ORAC GmbH & Co KG [member] Member relx:LexisNexisVerlagARDORACGmbHAndCoKGMember
1816 ORAC Gesellschaft m.b.H. [member] Member relx:ORACGesellschaftmbHMember
1817 Reed CEE GmbH [member] Member relx:ReedCEEGmbHMember
1818 Reed Messe Salzburg GmbH [member] Member relx:ReedMesseSalzburgGmbHMember
1819 Reed Messe Wien GmbH [member] Member relx:ReedMesseWienGmbHMember
1820 RELX Austria GmbH [member] Member relx:RELXAustriaGmbHMember
1821 System Stand Bau GmbH [member] Member relx:SystemStandBauGmbHMember
1822 LexisNexis BVBA [member] Member relx:LexisNexisBVBAMember
1823 First 4 Farming Europe NV [member] Member relx:FirstFourFarmingEuropeNVMember
1824 Fircosoft Brazil Consultoriae Servicos de lnformatica Ltda [member] Member relx:FircosoftBrazilConsultoriaeServicosDeLnformaticaLtdaMember
1825 Elsevier Editora Ltda [member] Member relx:ElsevierEditoraLtdaMember
1826 LexisNexis Informacoes e Sistemas Empresariais Ltda [member] Member relx:LexisnexisInformacoesESistemasEmpresariaisLtdaMember
1827 Lexis Nexis Serviços de Análise de Risco Ltda [member] Member relx:LexisnexisServicosDeAnaliseDeRiscoLtdaMember
1828 MLex Brasil Midia Mercadoligica Ltda [member] Member relx:MLexBrasilMidiaMercadoligicaLtdaMember
1829 Reed Exhibitions Alcantara Machado Ltda [member] Member relx:ReedExhibitionsAlcantaraMachadoLtdaMember
1830 SST Software do Brasil Ltda [member] Member relx:SSTSoftwareDoBrasilLtdaMember
1831 LexisNexis Canada Inc. [member] Member relx:LexisNexisCanadaIncMember
1832 Science-Metrix lnc [member] Member relx:ScienceMetrixLncMember
1833 Beijing Bakery China Exhibitions Co., Ltd [member] Member relx:BeijingBakeryChinaExhibitionsCoLtdMember
1834 ThreatMetrix (Canada) Inc [member] Member relx:ThreatMetrixCanadaIncMember
1835 Beijing Medtime Elsevier Education Technology Co., Ltd [member] Member relx:BeijingMedtimeElsevierEducationTechnologyCoLtdMember
1836 Beijing Reed Elsevier Science and Technology Co, Ltd [member] Member relx:BeijingReedElsevierScienceAndTechnologyCoLtdMember
1837 Beijing Reed Guanghe Exhibition Co., Ltd [member] Member relx:BeijingReedGuangheExhibitionCoLtdMember
1838 C-One Energy Co Ltd [member] Member relx:COneEnergyCoLtdMember
1839 Genilex Information Technology Co. Ltd. [member] Member relx:GenilexInformationTechnologyCoLtdMember
1840 ICIS Consulting (Beijing) Co Ltd [member] Member relx:ICISConsultingBeijingCoLtdMember
1841 KeAi Communications Co Ltd [member] Member relx:KeaiCommunicationsCoLtdMember
1842 MLex Consulting (Beijing) Co., Ltd [member] Member relx:MLexConsultingBeijingCoLtdMember
1843 LexisNexis Risk Solutions (Shanghai) Information Technologies Co., Ltd [member] Member relx:LexisNexisRiskSolutionsShanghaiInformationTechnologiesCoLtdMember
1844 Reed Elsevier Information Technology (Beijing) Co. Ltd. [member] Member relx:ReedElsevierInformationTechnologyBeijingCoLtdMember
1845 Reed Exhibitions (China) Co., Ltd [member] Member relx:ReedExhibitionsChinaCoLtdMember
1846 Reed Business Information (Shanghai) Co., Ltd [member] Member relx:ReedBusinessInformationShanghaiCoLtdMember
1847 Reed Exhibitions (Shanghai) Co. Ltd [member] Member relx:ReedExhibitionsShanghaiCoLtdMember
1848 Reed Hongda Exhibitions (Henan) Co., Ltd [member] Member relx:ReedHongdaExhibitionsHenanCoLtdMember
1849 Reed Huabai Exhibitions Beijing Co Ltd [Member] Member relx:ReedHuabaiExhibitionsBeijingCoLtdMember
1850 Reed Exhibitions Henjin Co., Ltd [member] Member relx:ReedExhibitionsHenjinCoLtdMember
1851 Reed Huabo Exhibitions (Shenzhen) Co., Ltd [member] Member relx:ReedHuaboExhibitionsShenzhenCoLtdMember
1852 Reed Huaqun ExhibitionsCo., Ltd [member] Member relx:ReedHuaqunExhibitionsCoLtdMember
1853 Reed Kuozhan Exhibitions (Shanghai) Co., Ltd [member] Member relx:ReedKuozhanExhibitionsShanghaiCoLtdMember
1854 Reed Sinopharm ExhibitionsCo., Ltd [member] Member relx:ReedSinopharmExhibitionsCoLtdMember
1855 RELX (China) Investment Co., Ltd [member] Member relx:RELXChinaInvestmentCoLtdMember
1856 Shanghai Datong Medical Information Technology Co., Ltd [member] Member relx:ShanghaiDatongMedicalInformationTechnologyCoLtdMember
1857 Shanghai SinoReal Exhibitions Co., Ltd [member] Member relx:ShanghaiSinorealExhibitionsCoLtdMember
1858 Elsevier Holding France SAS [member] Member relx:ElsevierHoldingFranceSASMember
1859 LexisNexis Business Information Solutions S.A. [member] Member relx:LexisNexisBusinessInformationSolutionsSAMember
1860 LexisNexis Business Information Solutions Holding S.A. [member] Member relx:LexisNexisBusinessInformationSolutionsHoldingSAMember
1861 LexisNexis International Development Services S. A. [member] Member relx:LexisNexisInternationalDevelopmentServicesSAMember
1862 Aries Medical Knowledge GmbH & Co KG [member] Member relx:AriesMedicalKnowledgeGmbHCoKGMember
1863 Aries Medical Knowledge Verwaltungsgesellschaft GmbH [member] Member relx:AriesMedicalKnowledgeVerwaltungsgesellschaftGmbHMember
1864 LexisNexis Risk Solutions S.A.S. [member] Member relx:LexisNexisRiskSolutionsSASMember
1865 Patent Sight GmbH [member] Member relx:PatentSightGmbHMember
1866 Elsevier A/S [member] Member relx:ElsevierASMember
1867 Reed Elsevier Denmark ApS [member] Member relx:ReedElsevierDenmarkApSMember
1868 Ascend China Holding Ltd [member] Member relx:AscendChinaHoldingLimitedMember
1869 Reed Business Information (China) Ltd [member] Member relx:ReedBusinessInformationLtdMember
1870 Reed Exhibitions Free Zone-LLC [member] Member relx:ReedExhibitionsFreeZoneLLCMember
1871 Reed Travel Group (Germany) GmbH [member] Member relx:ReedTravelGermanyGmbHMember
1872 RELX Middle East FZ-LLC [member] Member relx:RELXMiddleEastFZLLCMember
1873 JC Exhibition and Promotion Ltd [member] Member relx:JCExhibitionAndPromotionLimitedMember
1874 JYLN Sager Ltd [member] Member relx:JYLNSagerLimitedMember
1875 Elsevier Egypt LLC. Member relx:ElsevierEgyptLLCMember
1876 MLex Asia Ltd [member] Member relx:MLexAsiaLtdMember
1877 Reed Exhibitions Ltd [member] Member relx:ReedExhibitionsLimitedMember
1878 RELX (Greater China) Ltd [member] Member relx:RELXGreaterChinaLtdMember
1879 Elsevier Masson SAS [member] Member relx:ElsevierMassonSASMember
1880 Evoluprint SAS [member] Member relx:EVOLUPRINTSASMember
1881 Fircosoft SAS [member] Member relx:FircoSoftSASMember
1882 Comic Con India Private Ltd [member] Member relx:ComicConIndiaPrivateLimitedMember
1883 Gie Juris-Data [member] Member relx:GIEEDIDATAMember
1884 FircoSoft India Private Ltd [member] Member relx:FircoSoftIndiaPrivateLtdMember
1885 Gie Juris-Data [member] Member relx:GIEJURISDATAMember
1886 GIE PRK - Publicite Robert Krier [member] Member relx:GIEPRKPubliciteRobertKrierMember
1887 Reed ELsevier Publishing (India) Pvt. Ltd. [member] Member relx:ReedElsevierPublishingIndiaPvtLtdMember
1888 Reed Manch Exhibitions Private Ltd (70%) [member] Member relx:ReedManchExhibitionsPrivateLimitedMember
1889 ReedSI Exhibitions Private Ltd [member] Member relx:ReedSIExhibitionsPrivateLimitedMember
1890 Reed Triune Exhibitions Private Ltd (72%) [member] Member relx:ReedTriuneExhibitionsPrivateLimitedMember
1891 LexisNexis SA [member] Member relx:LEXISNEXISSAMember
1892 RELX India Private Ltd [member] Member relx:RELXIndiaPrivateLimitedMember
1893 Reed Exhibitions ISG SARL [member] Member relx:ReedExhibitionsISGSARLMember
1894 Reed Expositions France SAS [member] Member relx:REEDEXPOSITIONSFRANCESASMember
1895 PT Reed Panorama Exhibitions [member] Member relx:ReedPanoramaExhibitionsMember
1896 Reed Midem SAS [member] Member relx:ReedMIDEMSASMember
1897 Reed Organisation SAS [member] Member relx:REEDORGANISATIONSASMember
1898 RELX France S.A. [member] Member relx:RELXFranceSAMember
1899 PT Reed Exhibitions Indonesia [member] Member relx:PTReedExhibitionsIndonesiaMember
1900 SAFI SA [member] Member relx:SAFISAMember
1901 Elsevier GmbH [member] Member relx:ElsevierGmbHMember
1902 Elsevier Information Systems GmbH [member] Member relx:ElsevierInformationSystemsGmbHMember
1903 LexisNexis GmbH [member] Member relx:LexisNexisGmbHMember
1904 REC Publications GmbH [member] Member relx:RECPublicationsGmbHMember
1905 Reed Exhibitions (Germany) GmbH [member] Member relx:ReedExhibitionsGermanyGmbHMember
1906 Reed Exhibitions Deutschland GmbH [member] Member relx:ReedExhibitionsDeutschlandGmbHMember
1907 RELX Deutschland GmbH [member] Member relx:RELXDeutschlandGmbHMember
1908 Tschach Solutions GmbH [member] Member relx:TschachSolutionsGmbHMember
1909 Butterworth (Ireland) Ltd [member] Member relx:ButterworthIrelandLimitedMember
1910 Elsevier Services Ireland Ltd [member] Member relx:ElsevierServicesIrelandLimitedMember
1911 LexisNexis Risk Solutions (Ireland) Ltd Member relx:LexisNexisRiskSolutionsIrelandLtdMember
1912 Lexis Nexis Risk Solutions Europe Ltd Member relx:LexisNexisRiskSolutionsEuropeLtdMember
1913 Lexis Nexis Israel Ltd [member] Member relx:LexisNexisIsraelLtdMember
1914 Elsevier SRL [member] Member relx:ElsevierSRLMember
1915 ICIS Italia SRL [member] Member relx:ICISItaliaSRLMember
1916 Reed Exhibitions ISG Italy SRL [member] Member relx:ReedExhibitionsISGItalySRLMember
1917 Reed Exhibitions Italia SRL [member] Member relx:ReedExhibitionsItaliaSrlMember
1918 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
1919 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
1920 Ordinary shares [member] Member ifrs-full:OrdinarySharesMember
1921 Unlimited class B shares [member] Member relx:UnlimitedClassBSharesMember
1922 Registered capital [member] Member relx:RegisteredCapitalMember
1923 Quotas [member] Member relx:QuotasMember
1924 Quotas shares [member] Member relx:QuotasSharesMember
1925 Class A ordinary shares [member] Member relx:ClassAOrdinarySharesMember
1926 Unlimited class A shares [member] Member relx:UnlimitedClassASharesMember
1927 Unlimited class C shares [member] Member relx:UnlimitedClassCSharesMember
1928 Unlimited class D shares [member] Member relx:UnlimitedClassDSharesMember
1929 Unlimited class E shares [member] Member relx:UnlimitedClassESharesMember
1930 Unlimited class F shares [member] Member relx:UnlimitedClassFSharesMember
1931 Unlimited class G shares [member] Member relx:UnlimitedClassGSharesMember
1932 Unlimited class H shares [member] Member relx:UnlimitedClassHSharesMember
1933 Class A commonshares [member] Member relx:ClassACommonsharesMember
1934 Class B common shares [member] Member relx:ClassBCommonSharesMember
1935 Class A preferred shares [member] Member relx:ClassAPreferredSharesMember
1936 Class B preferred shares [member] Member relx:ClassBPreferredSharesMember
1937 Class C preferred shares [member] Member relx:ClassCPreferredSharesMember
1938 Class D preferred shares [member] Member relx:ClassDPreferredSharesMember
1939 Common Stock [member] Member relx:CommonStock1Member
1940 Class B voting Ordinary Shares [member] Member relx:ClassBVotingOrdinarySharesMember
1941 Class B ordinary shares [member] Member relx:ClassBOrdinarySharesMember
1942 Disclosure of transactions between related parties [line items] LineItems ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesLineItems
1943 Company name Concept (Text/String) For Period relx:NameOfRelatedParty
1944 Percentage of undertaking Concept (Percent) For Period relx:ProportionOfOwnershipInterestInRelatedUndertakings
1945 Reg office Concept (Text/String) For Period ifrs-full:AddressOfRegisteredOfficeOfEntity
1946 101570 - Disclosure - Related undertakings - Summary of Full list of Related Parties - Japan to United Kingdom (Detail) Network

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*

 http://relx.com/20181231/taxonomy/role/DisclosureRelatedUndertakingsSummaryOfFullListOfRelatedPartiesJapanToUnitedKingdomDetail
1947 Disclosure Of Transactions Between Related Parties [Table] Table

*

*

 ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesTable
1948 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
1949 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
1950 JAPAN Member country:JP
1951 Luxembourg [member] Member country:LU
1952 Korea (South) [member] Member country:KR
1953 Malaysia [member] Member country:MY
1954 South Africa [member] Member country:ZA
1955 Mexico. Member country:MX
1956 SINGAPORE Member country:SG
1957 Morocco [member] Member country:MA
1958 New Zealand [member] Member country:NZ
1959 Philippines. Member country:PH
1960 Poland [member] Member country:PL
1961 Russia [member] Member country:RU
1962 Saudi Arabia [member] Member country:SA
1963 Spain [member] Member country:ES
1964 Switzerland [member] Member country:CH
1965 Taiwan [member] Member country:TW
1966 Netherlands [member] Member country:NL
1967 Thailand [member] Member country:TH
1968 TURKEY Member country:TR
1969 United Kingdom [member] Member country:GB
1970 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
1971 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
1972 PatentSight Japan Inc [Member] Member relx:PatentSightJapanIncMember
1973 ThreatMetrix GK [Member] Member relx:ThreatMetrixGKMember
1974 Fircosoft Luxembourg Sarl [member] Member relx:FircosoftLuxembourgSarlMember
1975 Ascend Japan KK [member] Member relx:AscendJapanKKMember
1976 Elsevier Japan KK [member] Member relx:ElsevierJapanKkMember
1977 LexisNexis Japan KK [member] Member relx:LexisnexisJapanKkMember
1978 Reed Exhibitions Japan KK [member] Member relx:ReedExhibitionJapanMember
1979 Reed ISG Japan KK [member] Member relx:ReedISGJapanKKMember
1980 Elsevier Korea LLC [member] Member relx:ElsevierKoreaLlcMember
1981 Lexis Nexis Legal And Professional Service Korea Ltd [member] Member relx:LexisnexisLegalAndProfessionalServiceKoreaLtdMember
1982 Reed Exhibitions Korea Ltd [member] Member relx:ReedExhibitionsKoreaLimitedMember
1983 Reed Exporum Ltd [member] Member relx:ReedExporumLtdMember
1984 Reed K. Fairs Ltd seventy percentage [member] Member relx:ReedFairsLimitedSeventyPercentageMember
1985 LexisNexis Malaysia Sdn Bhd [member] Member relx:LexisnexisMalaysiaSdnBhdMember
1986 Reed Exhibitions Sdn Bhd [member] Member relx:ReedExhibitionsSdnBhdMember
1987 F I R C O S O F T South Africa Proprietary Limited Member relx:FIRCOSOFTSouthAfricaProprietaryLimitedMember
1988 Globalrange SA Pty Ltd [member] Member relx:GlobalrangeSAPtyLtdMember
1989 Korbitec (Pty) Ltd (90%) [member] Member relx:KorbitecProprietaryLimitedNinetyPercentageMember
1990 Masson-Doyma Mexico, S.A. [member] Member relx:MassondoymaMexicoSAMember
1991 Reed Exhibitions Mexico S.A. de C.V. [member] Member relx:ReedExhibitionsMexicoSAdeCVMember
1992 LexisNexis Academic (Pty) Ltd ninety percentage [member] Member relx:LexisNexisAcademicPtyLtdNinetyPercentageMember
1993 ThreatMetrixPTE Ltd [Member] Member relx:ThreatMetrixPTELtdMember
1994 LexisNexis (Pty) Ltd (90%) [member] Member relx:LexisNexisProprietaryLimitedNinetyPercentageMember
1995 Reed Exhibitions Morocco SARL [member] Member relx:ReedExhibitionsMoroccoSarlMember
1996 LexisNexis Risk Management (Pty) Ltd (90%) [member] Member relx:LexisnexisRiskManagementProprietaryLimitedNinetyPercentageMember
1997 LexisNexis NZ Ltd [member] Member relx:LexisnexisNZLimitedMember
1998 Reed Elsevier Shared Services (Philippines) Inc. [member] Member relx:ReedElsevierSharedServicesPhilippinesIncMember
1999 LegalPerfectTSoftware Solutions (Pty) Ltd [Member] Member relx:LegalPerfectTSoftwareSolutionsPtyLtdMember
2000 Elsevier sp. z.o.o. [member] Member relx:ElsevierspMember
2001 Ecwatech Company ZAO [member] Member relx:EcwatechCompanyZAOMember
2002 Property Payment Exchange (SA) (Pty) Ltd [member] Member relx:PropertyPaymentExchangeSAPtyLimitedNinetyPercentageMember
2003 LexisNexis OOO [member] Member relx:LexisNexisOOOMember
2004 Real estate events direct [member] Member relx:RealEstateEventsDirectOooMember
2005 Relx ooo [member] Member relx:RelxOOOMember
2006 Reed Sunaidi Exhibitions [member] Member relx:ReedSunaidiExhibitionsMember
2007 Elsevier (Singapore) Pte Ltd [member] Member relx:ElsevierSingaporePteLtdMember
2008 F4F Agriculture (Asia Pacific) Pte Ltd [member] Member relx:FFourFAgricultureAsiaPacificPteLtdMember
2009 Lexis-Nexis Philippines Pte Ltd [member] Member relx:LexisnexisPhilippinesPteLimitedMember
2010 Reed Business Information Pte Ltd [member] Member relx:ReedBusinessInformationPteLtdMember
2011 RE (HAPL) Pte Ltd [member] Member relx:REHAPLPteLtdMember
2012 RELX (Singapore) Pte. Ltd. [member] Member relx:RELXSingaporePteLtdMember
2013 SAFI Asia Pte Ltd fifty percentage [member] Member relx:SAFIAsiaPteLtdMember
2014 RELX (Pty) Ltd. [member] Member relx:RELXPtyLtdMember
2015 Reed Exhibitions (Pty) Ltd ninety percentage [member] Member relx:ReedExhibitionsPtyLimitedNinetyPercentageMember
2016 Reed Events Management Pty Ltd [Member] Member relx:ReedEventsManagementPtyLtdMember
2017 Reed Exhibitions Group (Pty) Limited [member] Member relx:ReedExhibitionsGroupPtyLimitedNinetyPercentageMember
2018 Reed Venue Management (Pty) Ltd [member] Member relx:ThebeReedVenueManagementPtyLimitedMember
2019 Winsearch Services (Pty) Ltd [member] Member relx:WinsearchServicesPtyLtdMember
2020 Elsevier Espana, S.L. [member] Member relx:ElsevierEspanaSLMember
2021 Elsevier finance SA [member] Member relx:ElsevierFinanceSAMember
2022 Fircosoft Schweiz GmbH [member] Member relx:FIRCOSOFTSchweizGmbHMember
2023 RELX risks SA [member] Member relx:RELXRisksSAMember
2024 RELX Swiss holdings SA [member] Member relx:RELXSwissHoldingsSAMember
2025 Elsevier Taiwan LLC [member] Member relx:ElsevierTaiwanLLCMember
2026 Misset Uitgeverij B.V. [Member] Member relx:MissetUitgeverijBVMember
2027 One Business B.V. [Member] Member relx:OneBusinessBVMember
2028 Reed Holding (ThaiLand) Co., Ltd [member] Member relx:ReedHoldingThailandCoLtdMember
2029 Reed Tradex Company Ltd [member] Member relx:ReedTradexCompanyLimitedMember
2030 Reed Tuyap Fuarcilik A.S. [member] Member relx:ReedTuyapFuarcilikMember
2031 AGRM Solutions C.V. [member] Member relx:AGRMSolutionsCVMember
2032 Elsevier B.V. [member] Member relx:ElsevierBVMember
2033 Elsevier Employment Services B.V. [member] Member relx:ElsevierEmploymentServicesBVMember
2034 LexisNexis Business Information Solutions B.V. [member] Member relx:LexisnexisBusinessInformationSolutionsBVMember
2035 ThreatMetrix BV [Member] Member relx:ThreatMetrixBVMember
2036 LexisNexis Univentio B.V. [member] Member relx:LexisNexisUniventioBVMember
2037 Reed Business B.V. [member] Member relx:ReedBusinessBVMember
2038 Elsevier STM Bilgi Hizmetleri Limited Sirketi [member] Member relx:ElsevierSTMBilgiHizmetleriLimitedSirketiMember
2039 RELX finance B.V. [member] Member relx:RELXFinanceBVMember
2040 RELX holdings B.V. [member] Member relx:RELXHoldingsBVMember
2041 RELX NederLand B.V. [member] Member relx:RELXNederlandBVMember
2042 RELX overseas B.V. [member] Member relx:RELXOverseasBVMember
2043 RELX US holdings (Amsterdam) B.V. [member] Member relx:RELXUSHoldingsAmsterdamBVMember
2044 Bradfield Brett Holdings Ltd [member] Member relx:BradfieldBrettHoldingsLimitedMember
2045 Butterworth and Co. (Publishers) Ltd [member] Member relx:ButterworthAndCoPublishersLimitedMember
2046 Adaptris Group Ltd [member] Member relx:AdaptrisGroupLimitedMember
2047 Adaptris Ltd [member] Member relx:AdaptrisLimitedMember
2048 Digital Foundry Network [Member] Member relx:DigitalFoundryNetworkMember
2049 Formpart (HPL) Ltd [Member] Member relx:FormpartHPLLtdMember
2050 Gamer Edition Ltd [member] Member relx:GamerEditionLtdMember
2051 Gamer Events Ltd [member] Member relx:GamerEventsLtdMember
2052 Gamer Network Ltd [member] Member relx:GamerNetworkLtdMember
2053 Hallplaza Ltd Member relx:HallplazaLtdMember
2054 Imbibe Media Ltd Member relx:ImbibeMediaLtdMember
2055 Indicium Financial Ltd Member relx:IndiciumFinancialLtdMember
2056 Information Handling Ltd Member relx:InformationHandlingLtdMember
2057 Butterworth and Co. (Overseas) Ltd [member] Member relx:ButterworthAndCoOverseasLimitedMember
2058 Insurance Initiatives Ltd Member relx:InsuranceInitiativesLtdMember
2059 Legend Exhibitions Ltd Member relx:LegendExhibitionsLtdMember
2060 Lexis Nexis Risk Solutions U K Ltd Member relx:LexisNexisRiskSolutionsUKLtdMember
2061 M C M Central Ltd Member relx:MCMCentralLtdMember
2062 M C M Expo Ltd Member relx:MCMExpoLtdMember
2063 Butterworths Ltd [member] Member relx:ButterworthsLimitedMember
2064 M C M Stategy Ltd Member relx:MCMStategyLtdMember
2065 Cordery Compliance Ltd [member] Member relx:CorderyComplianceLimitedMember
2066 Mendeley Ltd Member relx:MendeleyLtdMember
2067 Cordery Ltd [member] Member relx:CorderyLimitedMember
2068 M Lex Ltd Member relx:MLexLtdMember
2069 Crediva Ltd [member] Member relx:CredivaLimitedMember
2070 Moreover Technologies Ltd Member relx:MoreoverTechnologiesLtdMember
2071 Dew Events Ltd [member] Member relx:DewEventsLimitedMember
2072 Mosby International Ltd Member relx:MosbyInternationalLtdMember
2073 Drayton Legal Recoveries Ltd [member] Member relx:DraytonLegalRecoveriesLimitedMember
2074 Newsflo Ltd Member relx:NewsfloLtdMember
2075 E & P Events LLP [member] Member relx:EAndPEventsLLPMember
2076 Elsevier Ltd [member] Member relx:ElsevierLimitedMember
2077 Elsevier Life Sciences IP Ltd [member] Member relx:ElsevierLifeSciencesIpLtdMember
2078 Formpart (EPS) Ltd [member] Member relx:FormpartEPSLimitedMember
2079 Gamermania Ltd [member] Member relx:GamermaniaLtdMember
2080 George Philip Holdings Limited Member relx:GeorgePhilipHoldingsLimitedMember
2081 NLife Ltd [Member] Member relx:NLifeLtdMember
2082 Out There Gaming Ltd [member] Member relx:OutThereGamingLtdMember
2083 RE Directors (No.1) Limited [Member] Member relx:REDirectorsNoOneLimitedMember
2084 RE Directors (No.2) Limited [Member] Member relx:REDirectorsNoTwoLimitedMember
2085 Offshore Europe (Management) Ltd [member] Member relx:OffshoreEuropeManagementLimitedMember
2086 Offshore Europe Partnership [member] Member relx:OffshoreEuropePartnershipMember
2087 Oxford Spires Management Co; Ltd [member] Member relx:OxfordSpiresManagementCoLtdMember
2088 Peopletracer Ltd [member] Member relx:PeopletracerLimitedMember
2089 Prean Holdings Ltd [member] Member relx:PreanHoldingsLimitedMember
2090 RPS Ltd [Member] Member relx:RPSLtdMember
2091 Symbiotic Technologies Operations Ltd [member] Member relx:SymbioticTechnologiesOperationsLtdMember
2092 VG247 Ltd [member] Member relx:VG247LtdMember
2093 RE (SOE) Ltd [member] Member relx:RESOELimitedMember
2094 RE Secretaries Ltd [member] Member relx:RESecretariesLimitedMember
2095 Reed All Energy Ltd [member] Member relx:ReedAllEnergyLimitedMember
2096 Reed Business Information (Holdings) Ltd [member] Member relx:ReedBusinessInformationHoldingsLtdMember
2097 Reed Business Information (China) Ltd [member] Member relx:ReedBusinessInformationLtdMember
2098 Reed Consumer Books Ltd [member] Member relx:ReedConsumerBooksLimitedMember
2099 Reed Elsevier (UIG) Ltd [member] Member relx:ReedElsevierUIGLimitedMember
2100 Reed Elsevier Pension Trustee Ltd [member] Member relx:ReedElsevierPensionTrusteeLimitedMember
2101 Reed Events Ltd [member] Member relx:ReedEventsLimitedMember
2102 Reed Exhibitions Ltd [member] Member relx:ReedExhibitionsLimitedMember
2103 Reed Midem Ltd [member] Member relx:ReedMidemLimitedMember
2104 Reed Nominees Ltd [member] Member relx:ReedNomineesLimitedMember
2105 Reed Overseas Corporation Ltd [member] Member relx:ReedOverseasCorporationLimitedMember
2106 Reed Publishing Corporation Ltd [member] Member relx:ReedPublishingCorporationLimitedMember
2107 R E L X Holdings Limited Member relx:RELXHoldingsLimitedMember
2108 RELX (Investments) plc [member] Member relx:RELXInvestmentsPlcMember
2109 RELX (UK) Ltd [member] Member relx:RELXUKLIMITEDMember
2110 RELX Finance Ltd [member] Member relx:RELXFinanceLtdMember
2111 RELX Group plc [member] Member relx:RELXGroupPlcMember
2112 RELX Overseas Holdings Ltd [member] Member relx:RELXOverseasHoldingsLimitedMember
2113 REV Venture Partners Ltd [member] Member relx:REVVenturePartnersLimitedMember
2114 Tracesmart Group Ltd [member] Member relx:TracesmartGroupLimitedMember
2115 Tracesmart Ltd [member] Member relx:TracesmartLimitedMember
2116 Wunelli Ltd [member] Member relx:WunelliLimitedMember
2117 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
2118 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
2119 Common Stock [member] Member relx:CommonStock1Member
2120 Membership Interest [Member] Member relx:MembershipInterestMember
2121 Ordinary shares [member] Member ifrs-full:OrdinarySharesMember
2122 Registered capital [member] Member relx:RegisteredCapitalMember
2123 Preference shares [member] Member ifrs-full:PreferenceSharesMember
2124 Class A ordinary shares [member] Member relx:ClassAOrdinarySharesMember
2125 Participations shares [member] Member relx:ParticipationsSharesMember
2126 Class A-shares / Class B-shares [member] Member relx:ClassASharesClassBSharesMember
2127 Partnership interest [member] Member srt:PartnershipInterestMember
2128 E shares / RE shares [member] Member relx:ESharesRESharesMember
2129 Seven point five preferred income shares [member] Member relx:SevenPointFivePreferredIncomeSharesMember
2130 Class B ordinary shares [member] Member relx:ClassBOrdinarySharesMember
2131 Four point five cumulative preference shares [member] Member relx:FourPointFiveCumulativePreferenceSharesMember
2132 Deferred ordinary shares [member] Member relx:DeferredOrdinarySharesMember
2133 Class E Ordinary Shares [member] Member relx:ClassEOrdinarySharesMember
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2135 Company name Concept (Text/String) For Period relx:NameOfRelatedParty
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2137 Reg office Concept (Text/String) For Period ifrs-full:AddressOfRegisteredOfficeOfEntity
2138 101580 - Disclosure - Related undertakings - Summary of Full list of Related Parties - Japan to United Kingdom (Parenthetical) (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosureRelatedUndertakingsSummaryOfFullListOfRelatedPartiesJapanToUnitedKingdomParentheticalDetail
2139 Disclosure Of Transactions Between Related Parties [Table] Table

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 ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesTable
2140 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
2141 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
2142 United Kingdom [member] Member country:GB
2143 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
2144 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
2145 Bradfield Brett Holdings Ltd [member] Member relx:BradfieldBrettHoldingsLimitedMember
2146 Butterworth and Co. (Publishers) Ltd [member] Member relx:ButterworthAndCoPublishersLimitedMember
2147 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
2148 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
2149 Seven point five preferred income shares [member] Member relx:SevenPointFivePreferredIncomeSharesMember
2150 Four point five cumulative preference shares [member] Member relx:FourPointFiveCumulativePreferenceSharesMember
2151 Disclosure of transactions between related parties [line items] LineItems ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesLineItems
2152 Dividend per share Concept (Share) For Period ifrs-full:DividendsPaidOrdinarySharesPerShare
2153 101590 - Disclosure - Related undertakings - Summary of Full list of Related Parties - United States to Vietnam (Detail) Network

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 http://relx.com/20181231/taxonomy/role/DisclosureRelatedUndertakingsSummaryOfFullListOfRelatedPartiesUnitedStatesToVietnamDetail
2154 Disclosure Of Transactions Between Related Parties [Table] Table

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 ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesTable
2155 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
2156 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
2157 US [member] Member country:US
2158 Vietnam [Member] Member country:VN
2159 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
2160 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
2161 Flightstats Inc [member] Member relx:FlightstatsIncMember
2162 Gaming Business Asia LLC Fifty Percentage [member] Member relx:GamingBusinessAsiaMember
2163 Health Market Science Inc [member] Member relx:HealthMarketScienceIncMember
2164 IDGRBI China Publishers LLC [member] Member relx:IdgrbiChinaPublishersLlcMember
2165 Intelligize Inc [member] Member relx:IntelligizeIncMember
2166 Knovel Corporation [member] Member relx:KnovelCorporationMember
2167 LexisNexis Claims Solutions Inc [member] Member relx:LexisnexisClaimsSolutionsIncMember
2168 LexisNexis Coplogic Solutions Inc [member] Member relx:LexisnexisCoplogicSolutionsIncMember
2169 LexisNexis Of Puerto Rico Inc [member] Member relx:LexisnexisOfPuertoRicoIncMember
2170 LexisNexis Risk Assets Inc [member] Member relx:LexisnexisRiskAssetsIncMember
2171 LexisNexis Risk Data Management Inc [member] Member relx:LexisnexisRiskDataManagementIncMember
2172 LexisNexis Risk Holdings Inc [member] Member relx:LexisnexisRiskHoldingsIncMember
2173 Aries Systems Corporation [Member] Member relx:AriesSystemsCorporationMember
2174 LexisNexis Risk Solutions Inc [member] Member relx:LexisnexisRiskSolutionsIncMember
2175 LexisNexis Special Services Inc [member] Member relx:LexisnexisSpecialServicesIncMember
2176 LexisNexis VitalChek Network Inc [member] Member relx:LexisnexisVitalchekNetworkIncMember
2177 Managed Technology Services LLC [member] Member relx:ManagedTechnologyServicesLlcMember
2178 Matthew Bender And Company Inc [member] Member relx:MatthewBenderAndCompanyIncMember
2179 MLex US Inc [member] Member relx:MlexUsIncMember
2180 Enclarity Inc [member] Member relx:EnclarityIncMember
2181 PoliceReports US LLC [member] Member relx:PolicereportsUsLlcMember
2182 Portfolio Media Inc [member] Member relx:PortfolioMediaIncMember
2183 Gamer Network lnc. [Member] Member relx:GamerNetworkLncMember
2184 Reed Business Information Inc [member] Member relx:ReedBusinessInformationIncMember
2185 Reed Technology And Information Services Inc [member] Member relx:ReedTechnologyAndInformationServicesIncMember
2186 Lex Machina Inc [member] Member relx:LexMachinaIncMember
2187 RELX Inc [member] Member relx:RelxIncMember
2188 RELXUS Holdings Inc [member] Member relx:RelxUsHoldingsIncMember
2189 Reman Inc [member] Member relx:RemanIncMember
2190 REVIV Partnership LP [member] Member relx:REVIVPartnershipLpMember
2191 SAFI Americas LLC [member] Member relx:SafiAmericasLLCMember
2192 The Elsevier Foundation [member] Member relx:TheElsevierFoundationMember
2193 LexisNexis Rule of Law Foundation [member] Member relx:LexisNexisRuleOfLawFoundationMember
2194 RELX Capital Inc [member] Member relx:RelxCapitalIncMember
2195 Accuity Asset Verification Services Inc [member] Member relx:AccuityAssetVerificationServicesIncMember
2196 Science-Metrix Corporation [Member] Member relx:ScienceMetrixCorporationMember
2197 Symbiotic Technologies Operations Inc. [Member] Member relx:SymbioticTechnologiesOperationsIncMember
2198 Accuity Inc [member] Member relx:AccuityIncMember
2199 Derman Inc [member] Member relx:DermanIncMember
2200 Dunlap-Hanna Publishers [member] Member relx:DunlapHannaPublishersMember
2201 Elsevier Inc [member] Member relx:ElsevierIncMember
2202 Elsevier Holdings Inc. [member] Member relx:ElsevierHoldingsIncMember
2203 Elsevier Medical Information LLC [member] Member relx:ElsevierMedicalInformationLlcMember
2204 Elsevier STM Inc [member] Member relx:ElsevierStmIncMember
2205 ExitCare LLC [member] Member relx:ExitcareLlcMember
2206 ThreatMetrix [member] Member relx:ThreatMetrixMember
2207 Reed TradexVietnam LLC [member] Member relx:ReedTradexVietnamLLCMember
2208 The Reed Elsevier Ventures Two Thousand Five Partnership LP [member] Member relx:TheReedElsevierVenturesTwoThousandFivePartnershipLpMember
2209 The Reed Elsevier Ventures Two Thousand Six Partnership LP [member] Member relx:TheReedElsevierVenturesTwoThousandSixPartnershipLpMember
2210 The Reed Elsevier Ventures Two Thousand Eight Partnership LP [member] Member relx:TheReedElsevierVenturesTwoThousandEightPartnershipLpMember
2211 The Reed Elsevier Ventures Two Thousand Nine Partnership LP [member] Member relx:TheReedElsevierVenturesTwoThousandNinePartnershipLpMember
2212 The Reed Elsevier Ventures Two Thousand Ten Partnership LP [member] Member relx:TheReedElsevierVenturesTwoThousandTenPartnershipLpMember
2213 The Reed Elsevier Ventures Two Thousand Eleven Partnership LP [member] Member relx:TheReedElsevierVenturesTwoThousandElevenPartnershipLpMember
2214 The Reed Elsevier Ventures Two Thousand Twelve Partnership LP [member] Member relx:TheReedElsevierVenturesTwoThousandTwelvePartnershipLpMember
2215 The Reed Elsevier Ventures Two Thousand Thirteen Partnership LP [member] Member relx:TheReedElsevierVenturesTwoThousandThirteenPartnershipLpMember
2216 The Remick Publishers [member] Member relx:TheRemickPublishersMember
2217 World Compliance Inc [member] Member relx:WorldComplianceIncMember
2218 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
2219 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
2220 Common Stock [member] Member relx:CommonStock1Member
2221 Membership Interest [Member] Member relx:MembershipInterestMember
2222 Non Stock Corporation [Member] Member relx:NonStockCorporationMember
2223 Partnership interest [member] Member srt:PartnershipInterestMember
2224 Ordinary shares [member] Member ifrs-full:OrdinarySharesMember
2225 Disclosure of transactions between related parties [line items] LineItems ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesLineItems
2226 Company name Concept (Text/String) For Period relx:NameOfRelatedParty
2227 Percentage of undertaking Concept (Percent) For Period relx:ProportionOfOwnershipInterestInRelatedUndertakings
2228 Reg office Concept (Text/String) For Period ifrs-full:AddressOfRegisteredOfficeOfEntity

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