cm:Concept: us-gaap:DeferredCreditsAndOtherLiabilitiesCurrent
| Deferred Credits and Other Liabilities, Current |
| us-gaap:DeferredCreditsAndOtherLiabilitiesCurrent |
| 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 during the current period and current obligations not separately disclosed in the balance sheet (other liabilities, current). |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:DeferredCreditsAndOtherLiabilitiesCurrent |