cm:Concept: us-gaap:DeferredTaxAssetIntraEntityTransferAssetOtherThanInventory
| Deferred Tax Asset, Intra-entity Transfer, Asset Other than Inventory |
| us-gaap:DeferredTaxAssetIntraEntityTransferAssetOtherThanInventory |
| Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary difference from intra-entity transfer of asset within consolidated group. Excludes intra-entity transfer of inventory. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:DeferredTaxAssetIntraEntityTransferAssetOtherThanInventory |