cm:Member: us-gaap:LetterOfCreditMember
| Letter of Credit [Member] |
| us-gaap:LetterOfCreditMember |
| A document typically issued by a financial institution which acts as a guarantee of payment to a beneficiary, or as the source of payment for a specific transaction (for example, wiring funds to a foreign exporter if and when specified merchandise is accepted pursuant to the terms of the letter of credit). |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:LetterOfCreditMember |