| Standard label: | Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield, Period Increase (Decrease) |
| Name: | us-gaap:CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldPeriodIncreaseDecrease |
| Documentation: | Amount of increase (decrease) of the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans accounted for as debt securities, with evidence of deterioration of credit quality. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldPeriodIncreaseDecrease |
| Label | Role | Language |
| Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield, Period Increase (Decrease) | http://www.xbrl.org/2003/role/label | en-US |
| Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield, Period Increase (Decrease), Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 310 30 50 2 (a)(2) | http://fasb.org/us-gaap/role/ref/legacyRef | 310 |