| Standard label: | Certain Loans Acquired in Transfer Accounted for as Held-to-maturity Debt Securities, Acquired During Period, Cash Flows Expected to be Collected at Acquisition |
| Name: | us-gaap:CertainLoansAcquiredInTransferAccountedForAsHeldToMaturityDebtSecuritiesAcquiredDuringPeriodCashFlowsExpectedToBeCollectedAtAcquisition |
| Documentation: | Amount of cash flows expected to be collected at acquisition of acquired loans accounted for as held-to-maturity debt securities with evidence of deterioration of credit quality. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As Of (instant) |
| Balance type: | Debit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:CertainLoansAcquiredInTransferAccountedForAsHeldToMaturityDebtSecuritiesAcquiredDuringPeriodCashFlowsExpectedToBeCollectedAtAcquisition |
| Label | Role | Language |
| Certain Loans Acquired in Transfer Accounted for as Held-to-maturity Debt Securities, Acquired During Period, Cash Flows Expected to be Collected at Acquisition | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 310 30 50 2 (a)(3) | http://fasb.org/us-gaap/role/ref/legacyRef | 310 |
| FASB Accounting Standards Codification 310 30 15 2 | http://fasb.org/us-gaap/role/ref/legacyRef | 310 |