cm:Level3TextBlock: us-gaap:RedeemableNoncontrollingInterestTableTextBlock
| Redeemable Noncontrolling Interest [Table Text Block] |
| us-gaap:RedeemableNoncontrollingInterestTableTextBlock |
| Tabular disclosure of redeemable noncontrolling interest (as defined) included in the statement of financial position as either a liability or temporary equity. As of the date of the statement of financial position, such redeemable noncontrolling interest is currently redeemable, as defined, for cash or other assets of the entity at (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the entity. |
| cm:Level3TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:RedeemableNoncontrollingInterestTableTextBlock |
| RedeemableNoncontrollingInterest |