| Standard label: | Secured Borrowings, Gross, Difference, Amount |
| Name: | us-gaap:SecuredBorrowingsGrossDifferenceAmount |
| Documentation: | Amount of secured borrowings in excess of (less than) the liability for repurchase agreements and securities lending transactions, before offset, included in offsetting disclosures. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As Of (instant) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:SecuredBorrowingsGrossDifferenceAmount |
| Label | Role | Language |
| Secured Borrowings, Gross, Difference, Amount | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 860 30 50 7 (a)(1) | http://fasb.org/us-gaap/role/ref/legacyRef | 860 |