| Standard label: | Guaranty Assets |
| Name: | us-gaap:GuarantyAssets |
| Documentation: | The carrying amount of the contractual right to receive fees, as compensation in exchange for providing a guarantee to a third party, over life of the guarantee. |
| 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:GuarantyAssets |
| Label | Role | Language |
| Guaranty Assets | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 942 210 S99 1 (SX 210.9-03.10) | http://fasb.org/us-gaap/role/ref/legacyRef | 942 |