cm:Concept: us-gaap:DeferredTaxAssetsDeferredGainOnSaleLeasebackTransaction
| Deferred Tax Assets, Deferred Gain on Sale Leaseback Transaction |
| us-gaap:DeferredTaxAssetsDeferredGainOnSaleLeasebackTransaction |
| Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from a gain reported for tax purposes on sale and leaseback transactions in accordance with enacted tax laws. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:DeferredTaxAssetsDeferredGainOnSaleLeasebackTransaction |