| Standard label: | Additional Collateral, Aggregate Fair Value |
| Name: | us-gaap:AdditionalCollateralAggregateFairValue |
| Documentation: | The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period. |
| 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:AdditionalCollateralAggregateFairValue |
| Label | Role | Language |
| Additional Collateral, Aggregate Fair Value | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 815 10 50 4H (e) | http://fasb.org/us-gaap/role/ref/legacyRef | 815 |