| Standard label: | Securities Sold under Agreements to Repurchase [Member] |
| Name: | us-gaap:SecuritiesSoldUnderAgreementsToRepurchaseMember |
| Documentation: | The securities that an institution sells and agrees to repurchase (the identical or substantially the same securities) as a seller-borrower at a specified date for a specified price, also known as a repurchase agreement, or repo. Most repos involve obligations of the federal government or its agencies, but other financial instruments, such as commercial paper, banker's acceptances, and negotiable certificates of deposit, are sometimes used in repos. |
| 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:SecuritiesSoldUnderAgreementsToRepurchaseMember |
| Label | Role | Language |
| Securities Sold under Agreements to Repurchase [Member] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 825 10 50 10 | http://fasb.org/us-gaap/role/ref/legacyRef | 825 |