XML 62 R53.htm IDEA: XBRL DOCUMENT
v3.23.1

Derivative And Credit-Related Financial Instruments (Schedule Of Weighted Average Maturity And Interest Rates On Risk Management Cash Flow Swaps) (Details) - Variable rate loans - Swaps - cash flow - receive fixed/pay floating rate - Risk management purposes - Cash flow swap | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2023 | Dec. 31, 2022
Time to maturity (in years) |  | 4 years 6 months | 4 years 7 months 6 days
Receive rate | [1] | 2.34% | 2.35%
Pay rate | [1],[2] | 4.64% | 4.07%
[1] | Excludes forward starting swaps not effective as of the period shown. March 31, 2023 excluded $4.1 billion of forward starting swaps. December 31, 2022 excluded $4.6 billion of forward starting swaps.
[2] | Variable rates paid on receive fixed swaps designated as cash flow hedges are based on one-month LIBOR, BSBY or Secured Overnight Financing Rate (SOFR) rates in effect at March 31, 2023 and December 31, 2022. Derivative contracts with maturity dates beyond the LIBOR cessation date will fall back to the daily SOFR with a spread adjustment.

X
- Definition Average fixed interest rate related to the group of interest rate derivatives. + References No definition available. + Details
Name: | us-gaap_DerivativeAverageFixedInterestRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Average remaining period until maturity of the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_DerivativeAverageRemainingMaturity1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Average variable interest rate related to the group of interest rate derivatives. + References No definition available. + Details
Name: | us-gaap_DerivativeAverageVariableInterestRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_LoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | cma_DerivativePurposeAxis=cma_RiskManagementDerivativesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_SwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |