cm:Concept: us-gaap:ExtendedProductWarrantyAccrualPreexistingIncreaseDecrease
| Extended Product Warranty Accrual, Increase (Decrease) for Preexisting Warranties |
| us-gaap:ExtendedProductWarrantyAccrualPreexistingIncreaseDecrease |
| Amount of increase (decrease) in the extended product warranty accrual from changes in estimates attributable to preexisting product warranties. Excludes standard product warranties. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Credit |
| false |
| us-gaap:ExtendedProductWarrantyAccrualPreexistingIncreaseDecrease |