v3.25.3
Cover Document
Oct. 17, 2025
Cover [Abstract]  
Entity Central Index Key 0000028412
Entity Emerging Growth Company false
Written Communications false
Entity Incorporation, State or Country Code DE
Document Type 8-K
Document Period End Date Oct. 17, 2025
Entity Registrant Name COMERICA INCORPORATED
Entity Address, Address Line One 1717 Main Street, MC 6404
Entity Address, City or Town Dallas
Entity Address, State or Province TX
Entity Address, Postal Zip Code 75201
City Area Code 833
Local Phone Number 571-0486
Entity File Number 1-10706
Entity Tax Identification Number 38-1998421
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Amendment Flag false
Common Stock  
Cover [Abstract]  
Title of 12(b) Security Common Stock, $5 par value
Trading Symbol CMA
Security Exchange Name NYSE
Entity Listings [Line Items]  
Title of 12(b) Security Common Stock, $5 par value
Trading Symbol CMA
Security Exchange Name NYSE
Series B Preferred Stock  
Cover [Abstract]  
Title of 12(b) Security Depositary Shares, each representing a 1/40th interest in a share of 6.875% Fixed-Rate Reset Non-Cumulative Perpetual Preferred Stock, Series B
Trading Symbol CMA PrB
Security Exchange Name NYSE
Entity Listings [Line Items]  
Title of 12(b) Security Depositary Shares, each representing a 1/40th interest in a share of 6.875% Fixed-Rate Reset Non-Cumulative Perpetual Preferred Stock, Series B
Trading Symbol CMA PrB
Security Exchange Name NYSE