| Standard label: | Basis Swap [Member] |
| Name: | us-gaap:BasisSwapMember |
| Documentation: | Interest-rate swap contract where both rates are variable but are tied to different index rates. For example, but not limited to, one party's rate indexed to three-month London Interbank Offered Rate (LIBOR) while the other party's rate is indexed to six-month LIBOR. |
| Object type: | cm:Member |
| Data type: | [Member] (nonnum:domainItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | true |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:BasisSwapMember |
| Label | Role | Language |
| Basis Swap [Member] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 815 10 50 4D | http://fasb.org/us-gaap/role/ref/legacyRef | 815 |