| Standard label: | Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Level of Subordination |
| Name: | us-gaap:OtherThanTemporaryImpairmentLossesInvestmentsAvailableforsaleSecuritiesPortionRecognizedInEarningsNetQualitativeDisclosuresLevelOfSubordination |
| Documentation: | This item represents the current level of subordination of the entity's receipt of consideration should the assets underlying the security be liquidated when the level of subordination was considered as one of the potential factors in reaching a conclusion that the available-for-sale investments are other than temporarily impaired and the amount of such impairment determined to be related to credit loss recognized in earnings. |
| Object type: | cm:Concept |
| Data type: | Decimal (xbrli:decimalItemType) |
| Period type: | As Of (instant) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:OtherThanTemporaryImpairmentLossesInvestmentsAvailableforsaleSecuritiesPortionRecognizedInEarningsNetQualitativeDisclosuresLevelOfSubordination |
| Label | Role | Language |
| Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Level of Subordination | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 320 10 50 8A d. | http://fasb.org/us-gaap/role/ref/legacyRef | 320 |