| Standard label: | Interest and Dividend Income, Securities, Operating, Available-for-sale |
| Name: | us-gaap:InterestAndDividendIncomeSecuritiesAvailableForSale |
| Documentation: | Amount of operating dividend and interest income, including amortization and accretion of premiums and discounts, on available-for-sale securities. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | For Period (duration) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:InterestAndDividendIncomeSecuritiesAvailableForSale |
| Label | Role | Language |
| Interest and Dividend Income, Securities, Operating, Available-for-sale | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |