cm:Concept: us-gaap:SecurityOwnedNotReadilyMarketableFairValue
| Security Owned Not Readily Marketable, Fair Value |
| us-gaap:SecurityOwnedNotReadilyMarketableFairValue |
| Value of the not readily marketable security or category which has been determined by management based upon fair value methods, including pricing of similar securities and valuation techniques and is included in the schedule of financial condition or the balance sheet. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:SecurityOwnedNotReadilyMarketableFairValue |