cm:Concept: us-gaap:PledgedAssetsNotSeparatelyReportedRealEstate
| Pledged Assets, Not Separately Reported, Real Estate |
| us-gaap:PledgedAssetsNotSeparatelyReportedRealEstate |
| The carrying amount, as of the date of the latest financial statement presented, of real estate owned but transferred to serve as collateral for the payment of the related debt obligation, primarily a secured borrowing or repurchase agreement, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:PledgedAssetsNotSeparatelyReportedRealEstate |