| Standard label: | Other than Temporary Impairment Losses, Investments, Held-to-maturity Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Level of Subordination |
| Name: | us-gaap:OtherThanTemporaryImpairmentLossesInvestmentsHeldtomaturitySecuritiesPortionRecognizedInEarningsNetQualitativeDisclosuresLevelOfSubordination |
| 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 held-to-maturity investments are other than temporarily impaired and only the amount of impairment related to credit loss was 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:OtherThanTemporaryImpairmentLossesInvestmentsHeldtomaturitySecuritiesPortionRecognizedInEarningsNetQualitativeDisclosuresLevelOfSubordination |
| Label | Role | Language |
| Other than Temporary Impairment Losses, Investments, Held-to-maturity 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 |