cm:Concept: us-gaap:DeferredTaxesBusinessCombinationValuationAllowanceAllocatedToContributedCapital
| Deferred Taxes, Business Combination, Valuation Allowance, Allocated to Contributed Capital |
| us-gaap:DeferredTaxesBusinessCombinationValuationAllowanceAllocatedToContributedCapital |
| Amount of valuation allowance for tax benefit to be credited to shareholders' equity if tax benefit subsequently becomes realizable. Includes, but is not limited to, adjustment to opening balance of retained earnings for change in accounting principle or correction of error, gain (loss) in comprehensive income (loss) but excluded from net income (loss), deductible expenditure for income tax purposes reported as reduction of shareholders' equity, and deductible temporary difference existing at date of quasi-reorganization. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:DeferredTaxesBusinessCombinationValuationAllowanceAllocatedToContributedCapital |