| Standard label: | Pledged Assets Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment |
| Name: | us-gaap:PledgedAssetsSeparatelyReportedMortgageRelatedSecuritiesAvailableForSaleOrHeldForInvestment |
| Documentation: | The fair value, as of the date of each statement of financial position presented, of mortgage-related securities, classified as available for sale or held for investment, which are owned but transferred to serve as collateral for the payment of the related debt obligation, primarily a secured borrowing or repurchase agreement, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them. |
| 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:PledgedAssetsSeparatelyReportedMortgageRelatedSecuritiesAvailableForSaleOrHeldForInvestment |
| Label | Role | Language |
| Pledged Assets Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 860 30 45 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 860 |
| Part Of Roll Up: |
| us-gaap:PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAtFairValue |