v3.26.1
Document and Entity Information
Jul. 21, 2026
Cover [Abstract]  
Amendment Flag false
Entity Central Index Key 0000040729
Document Type 8-K
Document Period End Date Jul. 21, 2026
Entity File Number 1-3754
Entity Registrant Name ALLY FINANCIAL INC.
Entity Incorporation State Country Code DE
Entity Tax Identification Number 38-0572512
Entity Address, Address Line One 500 Woodward Ave.
Entity Address, Address Line Two Floor 10
Entity Address, City or Town Detroit
Entity Address, State or Province MI
Entity Address, Postal Zip Code 48226
City Area Code (866)
Local Phone Number 710-4623
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Security 12b Title Common Stock, par value $0.01 per share
Trading Symbol ALLY
Security Exchange Name NYSE
Entity Emerging Growth Company false