cm:Concept: us-gaap:DeferredTaxesBusinessCombinationValuationAllowanceAllocatedToReduceCapitalDescription
| Deferred Taxes, Business Combination, Valuation Allowance, Allocated to Reduce Capital, Description |
| us-gaap:DeferredTaxesBusinessCombinationValuationAllowanceAllocatedToReduceCapitalDescription |
| Description of circumstance resulting in valuation allowance being recorded for tax benefit to be credited directly to shareholders' equity. 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 |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:DeferredTaxesBusinessCombinationValuationAllowanceAllocatedToReduceCapitalDescription |