| Standard label: | Other than Temporary Impairment Losses, Investments, Reclassification Adjustment of Noncredit Portion Included in Net Income, Availabe-for-sale Securities, before Tax |
| Name: | us-gaap:OtherThanTemporaryImpairmentLossesInvestmentsReclassificationAdjustmentOfNoncreditPortionIncludedInNetIncomeAvailabeforsaleSecuritiesBeforeTax |
| Documentation: | Amount before tax of reclassification adjustment for other than temporary impairment (OTTI) related to factors other than credit loss on a previously impaired investment in available-for-sale debt security. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | For Period (duration) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:OtherThanTemporaryImpairmentLossesInvestmentsReclassificationAdjustmentOfNoncreditPortionIncludedInNetIncomeAvailabeforsaleSecuritiesBeforeTax |
| Label | Role | Language |
| Other than Temporary Impairment Losses, Investments, Reclassification Adjustment of Noncredit Portion Included in Net Income, Availabe-for-sale Securities, before Tax | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 320 10 45 9A | http://fasb.org/us-gaap/role/ref/legacyRef | 320 |