cm:Level2TextBlock: us-gaap:DeterioratedLoansTransferredInPolicy
| Deteriorated Loans Transferred in, Policy [Policy Text Block] |
| us-gaap:DeterioratedLoansTransferredInPolicy |
| Disclosure of accounting policy for how prepayments are considered in the determination of contractual cash flows and cash flows expected to be collected in the valuation of loans acquired through a transfer displaying evidence of deterioration of credit quality since origination for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable. |
| cm:Level2TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:DeterioratedLoansTransferredInPolicy |