cm:Concept: us-gaap:TreasuryStockRestrictions
| Treasury Stock, Restrictions |
| us-gaap:TreasuryStockRestrictions |
| This element represents a description of restrictions imposed by state laws on the entity's acquisition of its own [treasury] stock and the accounting treatment required to be applied in compliance with such restrictions. The information represented by this element does not include restrictions on the payment of dividends. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:TreasuryStockRestrictions |