cm:Concept: us-gaap:SubsidiaryOrEquityMethodInvesteeCumulativeProceedsReceivedOnAllTransactions
| Subsidiary or Equity Method Investee, Cumulative Proceeds Received on All Transactions |
| us-gaap:SubsidiaryOrEquityMethodInvesteeCumulativeProceedsReceivedOnAllTransactions |
| Cumulative amount of cash and other consideration received by subsidiary or equity method investee in exchange for shares or stock issued or sold. Include amounts of cash received, fair value of non-cash assets received, fair value of liabilities assumed, and fair value of any other forms of consideration. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Debit |
| false |
| us-gaap:SubsidiaryOrEquityMethodInvesteeCumulativeProceedsReceivedOnAllTransactions |