cm:Concept: us-gaap:DeferredCreditsAndOtherLiabilities
| Deferred Credits and Other Liabilities |
| us-gaap:DeferredCreditsAndOtherLiabilities |
| Total carrying amount as of the balance sheet date of unearned revenue or income, not otherwise specified in the taxonomy, which is expected to be taken into income in future periods and obligations not separately disclosed in the balance sheet (other liabilities). |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:DeferredCreditsAndOtherLiabilities |