| Standard label: | Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax |
| Name: | us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax |
| Documentation: | Amount, before tax, after reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | For Period (duration) |
| Balance type: | Debit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax |
| Label | Role | Language |
| Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax | http://www.xbrl.org/2003/role/label | en-US |
| Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax, Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 220 10 45 10A (i-k) | http://fasb.org/us-gaap/role/ref/legacyRef | 220 |
| FASB Accounting Standards Codification 220 10 45 11 | http://fasb.org/us-gaap/role/ref/legacyRef | 220 |
| Part Of Roll Up: |
| us-gaap:OtherComprehensiveIncomeLossBeforeTax |
| us-gaap:AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax |