| Standard label: | Valuation Allowance for Impairment of Recognized Servicing Assets, Balance |
| Name: | us-gaap:ValuationAllowanceForImpairmentOfRecognizedServicingAssetsBalance |
| Documentation: | Reflects the estimated amount of impairment as of the balance sheet date of recognized servicing assets that are being amortized in proportion to and over the period of estimated net servicing income or loss. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As Of (instant) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:ValuationAllowanceForImpairmentOfRecognizedServicingAssetsBalance |
| Label | Role | Language |
| Valuation Allowance for Impairment of Recognized Servicing Assets, Balance | http://www.xbrl.org/2003/role/label | en-US |
| Valuation Allowance for Impairment of Recognized Servicing Assets, Balance, Ending Balance | http://www.xbrl.org/2003/role/periodEndLabel | en-US |
| Valuation Allowance for Impairment of Recognized Servicing Assets, Balance, Beginning Balance | http://www.xbrl.org/2003/role/periodStartLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 860 50 50 4 (e)(1) | http://fasb.org/us-gaap/role/ref/legacyRef | 860 |