Loans and Leases - Accruing and Non-Accruing Loans by Class (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	$ 62,332	$ 61,853
Total Accruing	62,453	61,963
Current, non-accruing	444	372
Total Non- Accruing	605	602
Loans and leases	63,058	62,565
30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	112	89
Past due, non-accruing	26	51
90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	9	21
Past due, non-accruing	135	179
Commercial: | Commercial, financial, and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	34,131	33,222
Total Accruing	34,190	33,255
Current, non-accruing	153	101
Total Non- Accruing	211	173
Loans and leases	34,401	33,428
Commercial: | Commercial, financial, and industrial | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	58	32
Past due, non-accruing	15	26
Commercial: | Commercial, financial, and industrial | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	1	1
Past due, non-accruing	43	46
Commercial: | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	13,675	14,421
Commercial: | Credit Card and Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	154	174
Consumer:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	14,403	14,047
Consumer: | Consumer Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	14,216	13,845
Total Accruing	14,264	13,914
Current, non-accruing	53	50
Total Non- Accruing	139	133
Loans and leases	14,403	14,047
Consumer: | Consumer Real Estate | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	42	50
Past due, non-accruing	11	14
Consumer: | Consumer Real Estate | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	6	19
Past due, non-accruing	75	69
Consumer: | Credit Card and Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	572	662
Total Accruing	578	667
Current, non-accruing	0	0
Total Non- Accruing	1	2
Loans and leases	579	669
Consumer: | Credit Card and Other | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	4	4
Past due, non-accruing	0	1
Consumer: | Credit Card and Other | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	2	1
Past due, non-accruing	1	1
C&I | Commercial: | Commercial, financial, and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	30,206	29,751
Total Accruing	30,264	29,784
Current, non-accruing	153	101
Total Non- Accruing	211	173
Loans and leases	30,475	29,957
Nonaccrual, no allowance	199	172
C&I | Commercial: | Commercial, financial, and industrial | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	57	32
Past due, non-accruing	15	26
C&I | Commercial: | Commercial, financial, and industrial | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	1	1
Past due, non-accruing	43	46
Loans to mortgage companies | Commercial: | Commercial, financial, and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	3,925	3,471
Total Accruing	3,926	3,471
Current, non-accruing	0	0
Total Non- Accruing	0	0
Loans and leases	3,926	3,471
Loans to mortgage companies | Commercial: | Commercial, financial, and industrial | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	1	0
Past due, non-accruing	0	0
Loans to mortgage companies | Commercial: | Commercial, financial, and industrial | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	0	0
Past due, non-accruing	0	0
Commercial Real Estate | Commercial: | Commercial, financial, and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual, no allowance	251	287
Commercial Real Estate | Commercial: | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	13,675	14,421
Commercial Real Estate | Commercial real estate | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	13,413	14,124
Total Accruing	13,421	14,127
Current, non-accruing	238	221
Total Non- Accruing	254	294
Loans and leases	13,675	14,421
Commercial Real Estate | Commercial real estate | Commercial real estate | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	8	3
Past due, non-accruing	0	10
Commercial Real Estate | Commercial real estate | Commercial real estate | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	0	0
Past due, non-accruing	16	63
HELOC | Consumer: | Consumer Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	2,096	2,045
Total Accruing	2,111	2,058
Current, non-accruing	19	19
Total Non- Accruing	34	34
Loans and leases	2,145	2,092
Nonaccrual, no allowance	3	3
HELOC | Consumer: | Consumer Real Estate | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	15	11
Past due, non-accruing	5	4
HELOC | Consumer: | Consumer Real Estate | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	0	2
Past due, non-accruing	10	11
R E Installment Loans | Consumer: | Consumer Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	12,120	11,800
Total Accruing	12,153	11,856
Current, non-accruing	34	31
Total Non- Accruing	105	99
Loans and leases	12,258	11,955
Nonaccrual, no allowance	10	9
R E Installment Loans | Consumer: | Consumer Real Estate | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	27	39
Past due, non-accruing	6	10
R E Installment Loans | Consumer: | Consumer Real Estate | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	6	17
Past due, non-accruing	65	58
Credit card | Consumer: | Credit Card and Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	232	262
Total Accruing	237	265
Current, non-accruing	0	0
Total Non- Accruing	0	0
Loans and leases	237	265
Credit card | Consumer: | Credit Card and Other | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	3	2
Past due, non-accruing	0	0
Credit card | Consumer: | Credit Card and Other | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	2	1
Past due, non-accruing	0	0
Other | Consumer: | Credit Card and Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	340	400
Total Accruing	341	402
Current, non-accruing	0	0
Total Non- Accruing	1	2
Loans and leases	342	404
Other | Consumer: | Credit Card and Other | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	1	2
Past due, non-accruing	0	1
Other | Consumer: | Credit Card and Other | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	0	0
Past due, non-accruing	$ 1	$ 1