cm:Concept: us-gaap:PreferredStockValueOutstanding
| Preferred Stock, Value, Outstanding |
| us-gaap:PreferredStockValueOutstanding |
| Value of all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by shareholders, which is net of related treasury stock. May be all or a portion of the number of preferred shares authorized. These shares represent the ownership interest of the preferred shareholders. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:PreferredStockValueOutstanding |