| Standard label: | Deposits [Member] |
| Name: | us-gaap:DepositsMember |
| Documentation: | Amounts held on account by the entity representing a liability to the depositor. Deposits may take various forms (for example, demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits) and may be categorized in multiple ways (such as, foreign and domestic, interest and noninterest bearing). |
| 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:DepositsMember |
| Label | Role | Language |
| Deposits [Member] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 942 230 45 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 942 |