cm:Concept: us-gaap:RestrictedCashAndCashEquivalentItemPurpose
| Restricted Cash and Cash Equivalent Item, Purpose (Deprecated 2017-01-31) |
| us-gaap:RestrictedCashAndCashEquivalentItemPurpose |
| State the reason and intention for the restriction upon the specific item of restricted cash or cash equivalents being disclosed. In general, restrictions of cash and cash equivalents limit the entity's ability to withdraw or use the amount. Restrictions may include contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:RestrictedCashAndCashEquivalentItemPurpose |