cm:Level1TextBlock: us-gaap:AccountingForCertainLoansAndDebtSecuritiesAcquiredInTransferDisclosureTextBlock
| Accounting for Certain Loans and Debt Securities Acquired in Transfer Disclosure [Text Block] |
| us-gaap:AccountingForCertainLoansAndDebtSecuritiesAcquiredInTransferDisclosureTextBlock |
| The entire disclosure for certain contractual rights to receive money on demand or on fixed or determinable dates with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable. |
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| us-gaap:AccountingForCertainLoansAndDebtSecuritiesAcquiredInTransferDisclosureTextBlock |