cm:Concept: us-gaap:ClosedBlockDividendObligationAssumptions
| Closed Block Dividend Obligation, Assumptions |
| us-gaap:ClosedBlockDividendObligationAssumptions |
| Methodology and assumptions underlying the calculations of the excess of the cumulative actual closed block earnings over the expected (actuarially determined) closed block earnings for the period. The excess will result in future dividends to closed block policyholders, unless offset by less favorable than expected future performance of the closed block. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ClosedBlockDividendObligationAssumptions |