Asset Quality - Schedule of Amortized Cost Basis of Modified Loans That Subsequently Defaulted (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	$ 1	$ 30	$ 31	$ 48
Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	0	28	0	28
Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	0	1	21	17
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	0	0	7	0
Combination
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	1	1	3	3
Total commercial real estate loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		1	9	18
Total commercial real estate loans | Commercial and Industrial | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		0	0	0
Total commercial real estate loans | Commercial and Industrial | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		1	2	17
Total commercial real estate loans | Commercial and Industrial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		0	7	0
Total commercial real estate loans | Commercial and Industrial | Combination
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		0	0	1
Total commercial real estate loans | Total commercial real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment			19	29
Total commercial real estate loans | Total commercial real estate loans | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment			0	28
Total commercial real estate loans | Total commercial real estate loans | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment			19	0
Total commercial real estate loans | Total commercial real estate loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment			0	0
Total commercial real estate loans | Total commercial real estate loans | Combination
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment			0	1
Total commercial real estate loans | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		29	19	29
Total commercial real estate loans | Commercial mortgage | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		28	0	28
Total commercial real estate loans | Commercial mortgage | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		0	19	0
Total commercial real estate loans | Commercial mortgage | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		0	0	0
Total commercial real estate loans | Commercial mortgage | Combination
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		1	0	1
Total commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		30	28	47
Total commercial loans | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		28	0	28
Total commercial loans | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		1	21	17
Total commercial loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		0	7	0
Total commercial loans | Combination
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		$ 1	0	2
Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	1		3	1
Total consumer loans | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	0		0	0
Total consumer loans | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	0		0	0
Total consumer loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	0		0	0
Total consumer loans | Combination
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	1		3	1
Total consumer loans | Real estate — residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment			1
Total consumer loans | Real estate — residential mortgage | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment			0
Total consumer loans | Real estate — residential mortgage | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment			0
Total consumer loans | Real estate — residential mortgage | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment			0
Total consumer loans | Real estate — residential mortgage | Combination
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment			1
Total consumer loans | Home equity loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment				1
Total consumer loans | Home equity loans | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment				0
Total consumer loans | Home equity loans | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment				0
Total consumer loans | Home equity loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment				0
Total consumer loans | Home equity loans | Combination
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment				$ 1
Total consumer loans | Credit cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	1		2
Total consumer loans | Credit cards | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	0		0
Total consumer loans | Credit cards | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	0		0
Total consumer loans | Credit cards | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	0		0
Total consumer loans | Credit cards | Combination
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	$ 1		$ 2