XML 99 R82.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Derivative And Credit-Related Financial Instruments Derivative And Credit-Related Financial Instruments (Schedule of Effects of Fair Value Hedging on the Consolidated Statements of Comprehensive Income) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Statement [Line Items] |  |  |  |
Interest on medium- and long-term debt | [1] | $ 378 | $ 87 | $ 35
Swaps - fair value - receive fixed/pay floating | Risk management purposes | Interest Rate Swap [Member] |  |  |  |
Statement [Line Items] |  |  |  |
Interest rate contract: Hedged items interest expense |  | 265 | 112 | 102
Interest rate contracts: Derivatives designated as hedging instruments net interest income |  | $ 113 | $ (25) | $ (68)
[1] | Includes the effects of hedging.

X
- Definition [Line Items] for Effects of fair value hedging of the derivative instruments used for managing interest rate risk on the Consolidated Statements o Comprehensive Income [Table] + References No definition available. + Details
Name: | cma_EffectsoffairvaluehedgingontheConsolidatedStatementsoComprehensiveIncomeLineItems
Namespace Prefix: | cma_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest expense on hedged medium- and long-term debt + References No definition available. + Details
Name: | cma_Interestexpenseonhedgedmediumandlongtermdebt
Namespace Prefix: | cma_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 815 -SubTopic 25 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480238/815-25-50-1 + Details
Name: | us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Aggregate amount of interest paid or due on all long-term debt. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1402 -Paragraph (a) -Publisher SEC Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1402 -Paragraph (b) -Subparagraph (1) -Publisher SEC Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.8) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1 + Details
Name: | us-gaap_InterestExpenseLongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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