v3.25.1
Loans and ACL - Loans Modified During Period That Were in Payment Default (Details) - USD ($)
$ in Millions
 12 Months Ended
Mar. 31, 2025
Dec. 31, 2024
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default $ 256 $ 161
Renewals    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 55 21
Extended Maturity [Member]    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 16 15
Contractual Interest Rate Adjustments    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 3 2
Capitalizations    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 5 6
Payment Delays    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 135 76
Combination - Capitalization and Term Extension    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 34 33
Other    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 8 8
Commercial: | Commercial and industrial    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 55 18
Commercial: | Commercial and industrial | Renewals    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 55 18
Commercial: | Commercial and industrial | Extended Maturity [Member]    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Commercial: | Commercial and industrial | Contractual Interest Rate Adjustments    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Commercial: | Commercial and industrial | Capitalizations    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Commercial: | Commercial and industrial | Payment Delays    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Commercial: | Commercial and industrial | Combination - Capitalization and Term Extension    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Commercial: | Commercial and industrial | Other    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Commercial: | CRE    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default   3
Commercial: | CRE | Renewals    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default   3
Commercial: | CRE | Extended Maturity [Member]    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default   0
Commercial: | CRE | Contractual Interest Rate Adjustments    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default   0
Commercial: | CRE | Capitalizations    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default   0
Commercial: | CRE | Payment Delays    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default   0
Commercial: | CRE | Combination - Capitalization and Term Extension    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default   0
Commercial: | CRE | Other    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default   0
Consumer: | Residential mortgage    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 136 102
Consumer: | Residential mortgage | Renewals    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Consumer: | Residential mortgage | Extended Maturity [Member]    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 14 13
Consumer: | Residential mortgage | Contractual Interest Rate Adjustments    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Consumer: | Residential mortgage | Capitalizations    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 5 6
Consumer: | Residential mortgage | Payment Delays    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 77 44
Consumer: | Residential mortgage | Combination - Capitalization and Term Extension    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 34 33
Consumer: | Residential mortgage | Other    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 6 6
Consumer: | Indirect auto    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 61 35
Consumer: | Indirect auto | Renewals    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Consumer: | Indirect auto | Extended Maturity [Member]    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 1 1
Consumer: | Indirect auto | Contractual Interest Rate Adjustments    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Consumer: | Indirect auto | Capitalizations    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Consumer: | Indirect auto | Payment Delays    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 58 32
Consumer: | Indirect auto | Combination - Capitalization and Term Extension    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Consumer: | Indirect auto | Other    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 2 2
Consumer: | Other consumer    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 1 1
Consumer: | Other consumer | Renewals    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Consumer: | Other consumer | Extended Maturity [Member]    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 1 1
Consumer: | Other consumer | Contractual Interest Rate Adjustments    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Consumer: | Other consumer | Capitalizations    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Consumer: | Other consumer | Payment Delays    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Consumer: | Other consumer | Combination - Capitalization and Term Extension    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Consumer: | Other consumer | Other    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Credit card    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 3 2
Credit card | Renewals    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Credit card | Extended Maturity [Member]    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Credit card | Contractual Interest Rate Adjustments    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 3 2
Credit card | Capitalizations    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Credit card | Payment Delays    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Credit card | Combination - Capitalization and Term Extension    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default 0 0
Credit card | Other    
Financing Receivable, Modified, Subsequent Default [Line Items]    
Modifications Made in the Current Period That Were in Payment Default $ 0 $ 0