cm:Concept: us-gaap:JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrustNoncurrent
| Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust, Noncurrent |
| us-gaap:JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrustNoncurrent |
| The noncurrent portion of the carrying value of junior subordinated long-term debt owed to unconsolidated subsidiary trusts as of the balance sheet date. Such debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets and was initially scheduled to be repaid after one year or beyond the normal operating cycle if longer. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrustNoncurrent |