| Standard label: | Closed Portfolio and Beneficial Interest, Last-of-Layer, Amortized Cost |
| Name: | us-gaap:ClosedPortfolioAndBeneficialInterestLastOfLayerAmortizedCost |
| Documentation: | Amortized cost of closed portfolio of prepayable financial asset and beneficial interest secured by prepayable financial instrument, used to designate hedging relationship in which hedged item is last layer expected to be remaining at end of hedging relationship. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As Of (instant) |
| Balance type: | Debit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:ClosedPortfolioAndBeneficialInterestLastOfLayerAmortizedCost |
| Label | Role | Language |
| Closed Portfolio and Beneficial Interest, Last-of-Layer, Amortized Cost | http://www.xbrl.org/2003/role/label | en-US |
| Closed Portfolio and Beneficial Interest, Last-of-Layer, Amortized Cost, Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 815 10 50 4EEE (a) | http://www.xbrl.org/2003/role/disclosureRef | 815 |