cm:Concept: us-gaap:AssetsDesignatedToClosedBlockCashAndCashEquivalents
| Assets Designated to Closed Block, Cash and Cash Equivalents |
| us-gaap:AssetsDesignatedToClosedBlockCashAndCashEquivalents |
| Cash and highly liquid, safe investments that can be readily converted into cash (cash equivalents) allocated to the segregated group of participating or dividend-paying policies and contracts identified as the closed block. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:AssetsDesignatedToClosedBlockCashAndCashEquivalents |