cm:Concept: us-gaap:PresentValueOfFutureInsuranceProfitsPercentageOfAmortizationExpenseYearFour
| Present Value of Future Insurance Profits, Percentage of Amortization Expense, Year Four |
| us-gaap:PresentValueOfFutureInsuranceProfitsPercentageOfAmortizationExpenseYearFour |
| Percentage of amortization expense expected to be recognized during fourth fiscal year following latest fiscal year for present value of future profits of insurance contract acquired in business combination. |
| cm:Concept |
| Percent (num:percentItemType) |
| As Of (instant) |
| (no balance type) |
| false |
| us-gaap:PresentValueOfFutureInsuranceProfitsPercentageOfAmortizationExpenseYearFour |