| Standard label: | Payments to Acquire Mortgage Servicing Rights (MSR) | 
| Name: | us-gaap:PaymentsToAcquireMortgageServicingRightsMSR | 
| Documentation: | The cash outflow to obtain servicing rights, which contractually entitle the servicer to receive fees and ancillary revenues for performing billing, collection, disbursement and recordkeeping services in connection with a mortgage portfolio. Rights may be obtained via (1) acquisition or assumption of a servicing obligation that does not relate to financial assets of the servicer or its consolidated affiliates; or (2) by originating mortgage loans and then (a) transferring the loans to a Variable Interest Entity (VIE) in a transaction that meets the necessary transfer and classification requirements, or (b) transferring the loans in a transaction that meets the requirements for sale accounting. | 
| 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:PaymentsToAcquireMortgageServicingRightsMSR | 
| Label | Role | Language | 
| Payments to Acquire Mortgage Servicing Rights (MSR) | http://www.xbrl.org/2003/role/label | en-US | 
| Reference | Role | Topic | 
| FASB Accounting Standards Codification 230 10 45 13 | http://fasb.org/us-gaap/role/ref/legacyRef | 230 | 
| FASB Accounting Standards Codification 860 50 25 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 860 | 
| Part Of Roll Up: | 
| us-gaap:PaymentsForProceedsFromMortgageServicingRights |