Loans and Leases - Accruing and Non-Accruing Loans by Class (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	$ 62,545	$ 61,853
Total Accruing	62,667	61,963
Current, non-accruing	342	372
Total Non- Accruing	593	602
Loans and leases	63,260	62,565
30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	114	89
Past due, non-accruing	122	51
90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	8	21
Past due, non-accruing	129	179
Commercial: | Commercial, financial, and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	34,083	33,222
Total Accruing	34,134	33,255
Current, non-accruing	166	101
Total Non- Accruing	225	173
Loans and leases	34,359	33,428
Commercial: | Commercial, financial, and industrial | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	50	32
Past due, non-accruing	4	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	55	46
Commercial: | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	13,936	14,421
Commercial: | Credit Card and Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	162	174
Consumer:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	14,368	14,047
Consumer: | Consumer Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	14,196	13,845
Total Accruing	14,237	13,914
Current, non-accruing	52	50
Total Non- Accruing	131	133
Loans and leases	14,368	14,047
Consumer: | Consumer Real Estate | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	35	50
Past due, non-accruing	23	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	56	69
Consumer: | Credit Card and Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	592	662
Total Accruing	596	667
Current, non-accruing	0	0
Total Non- Accruing	1	2
Loans and leases	597	669
Consumer: | Credit Card and Other | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	3	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	1	1
Past due, non-accruing	1	1
C&I | Commercial: | Commercial, financial, and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	30,025	29,751
Total Accruing	30,076	29,784
Current, non-accruing	166	101
Total Non- Accruing	225	173
Loans and leases	30,301	29,957
Nonaccrual, no allowance	207	172
C&I | Commercial: | Commercial, financial, and industrial | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	50	32
Past due, non-accruing	4	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	55	46
Loans to mortgage companies | Commercial: | Commercial, financial, and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	4,058	3,471
Total Accruing	4,058	3,471
Current, non-accruing	0	0
Total Non- Accruing	0	0
Loans and leases	4,058	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	0	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	228	287
Commercial Real Estate | Commercial: | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	13,936	14,421
Commercial Real Estate | Commercial real estate | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	13,674	14,124
Total Accruing	13,700	14,127
Current, non-accruing	124	221
Total Non- Accruing	236	294
Loans and leases	13,936	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	26	3
Past due, non-accruing	95	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	17	63
HELOC | Consumer: | Consumer Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	2,084	2,045
Total Accruing	2,099	2,058
Current, non-accruing	18	19
Total Non- Accruing	29	34
Loans and leases	2,128	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	12	11
Past due, non-accruing	4	4
HELOC | Consumer: | Consumer Real Estate | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	3	2
Past due, non-accruing	7	11
R E Installment Loans | Consumer: | Consumer Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	12,112	11,800
Total Accruing	12,138	11,856
Current, non-accruing	34	31
Total Non- Accruing	102	99
Loans and leases	12,240	11,955
Nonaccrual, no allowance	12	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	23	39
Past due, non-accruing	19	10
R E Installment Loans | Consumer: | Consumer Real Estate | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	3	17
Past due, non-accruing	49	58
Credit card | Consumer: | Credit Card and Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	245	262
Total Accruing	247	265
Current, non-accruing	0	0
Total Non- Accruing	0	0
Loans and leases	247	265
Credit card | 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	0
Credit card | Consumer: | Credit Card and Other | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	1	1
Past due, non-accruing	0	0
Other | Consumer: | Credit Card and Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, accruing	347	400
Total Accruing	349	402
Current, non-accruing	0	0
Total Non- Accruing	1	2
Loans and leases	350	404
Other | Consumer: | Credit Card and Other | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due, accruing	2	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