cm:Member: us-gaap:USTreasurySecuritiesMember
| US Treasury Securities [Member] |
| us-gaap:USTreasurySecuritiesMember |
| This category includes information about debt securities issued by the United States Department of the Treasury and backed by the United States government. Such securities primarily consist of treasury bills (short-term maturities - one year or less), treasury notes (intermediate term maturities - two to ten years), and treasury bonds (long-term maturities - ten to thirty years). |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:USTreasurySecuritiesMember |