cm:Concept: us-gaap:ProceedsFromAnnuitiesAndInvestmentCertificates
| Proceeds from Annuities and Investment Certificates |
| us-gaap:ProceedsFromAnnuitiesAndInvestmentCertificates |
| The cash inflow from an insurance contract under which the policy holder make a lump sum payment or a series of payments in exchange for periodic payments to the policyholder beginning immediately or at some future date. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Debit |
| false |
| us-gaap:ProceedsFromAnnuitiesAndInvestmentCertificates |