Loans and Leases - Accruing And Non-Accruing Loans By Class (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, Accruing	$ 54,477	$ 54,436
Total Accruing	54,680	54,584
Current, Non-Accruing	180	182
Total Non- Accruing	332	275
Loans and leases	55,012	54,859
30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	180	108
Past Due, Non-Accruing	45	7
90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	23	40
Past Due, Non-Accruing	107	86
Commercial | Commercial, financial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, Accruing	30,567	30,885
Total Accruing	30,645	30,943
Current, Non-Accruing	91	97
Total Non- Accruing	153	125
Loans and leases	30,798	31,068
Commercial | Commercial, financial and industrial | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	72	53
Past Due, Non-Accruing	27	1
Commercial | Commercial, financial and industrial | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	6	5
Past Due, Non-Accruing	35	27
Commercial | Commercial, financial and industrial | C&I
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, Accruing	26,672	26,367
Total Accruing	26,750	26,425
Current, Non-Accruing	91	97
Total Non- Accruing	153	125
Loans and leases	26,903	26,550
Nonaccrual, no allowance	136	99
Commercial | Commercial, financial and industrial | C&I | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	72	53
Past Due, Non-Accruing	27	1
Commercial | Commercial, financial and industrial | C&I | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	6	5
Past Due, Non-Accruing	35	27
Commercial | Commercial, financial and industrial | Loans to mortgage companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, Accruing	3,895	4,518
Total Accruing	3,895	4,518
Current, Non-Accruing	0	0
Total Non- Accruing	0	0
Loans and leases	3,895	4,518
Commercial | Commercial, financial and industrial | Loans to mortgage companies | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	0	0
Past Due, Non-Accruing	0	0
Commercial | Commercial, financial and industrial | Loans to mortgage companies | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	0	0
Past Due, Non-Accruing	0	0
Commercial | Commercial, financial and industrial | CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual, no allowance	11	5
Commercial | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	12,487	12,109
Commercial | Commercial real estate | CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, Accruing		12,087
Total Accruing		12,100
Current, Non-Accruing		6
Total Non- Accruing		9
Loans and leases	12,487	12,109
Commercial | Commercial real estate | CRE | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing		13
Past Due, Non-Accruing		1
Commercial | Commercial real estate | CRE | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing		0
Past Due, Non-Accruing		2
Commercial real estate | Commercial real estate | CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, Accruing	12,427
Total Accruing	12,476
Current, Non-Accruing	7
Total Non- Accruing	11
Loans and leases	12,487
Commercial real estate | Commercial real estate | CRE | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	49
Past Due, Non-Accruing	1
Commercial real estate | Commercial real estate | CRE | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	0
Past Due, Non-Accruing	3
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	10,874	10,772
Consumer | Consumer Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, Accruing	10,644	10,564
Total Accruing	10,709	10,634
Current, Non-Accruing	81	78
Total Non- Accruing	165	138
Loans and leases	10,874	10,772
Consumer | Consumer Real Estate | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	51	37
Past Due, Non-Accruing	16	5
Consumer | Consumer Real Estate | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	14	33
Past Due, Non-Accruing	68	55
Consumer | Consumer Real Estate | HELOC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, Accruing	1,825	1,906
Total Accruing	1,847	1,919
Current, Non-Accruing	35	34
Total Non- Accruing	47	45
Loans and leases	1,894	1,964
Nonaccrual, no allowance	7	7
Consumer | Consumer Real Estate | HELOC | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	17	7
Past Due, Non-Accruing	4	2
Consumer | Consumer Real Estate | HELOC | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	5	6
Past Due, Non-Accruing	8	9
Consumer | Consumer Real Estate | Real estate installment loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, Accruing	8,819	8,658
Total Accruing	8,862	8,715
Current, Non-Accruing	46	44
Total Non- Accruing	118	93
Loans and leases	8,980	8,808
Nonaccrual, no allowance	7	50
Consumer | Consumer Real Estate | Real estate installment loans | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	34	30
Past Due, Non-Accruing	12	3
Consumer | Consumer Real Estate | Real estate installment loans | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	9	27
Past Due, Non-Accruing	60	46
Consumer | Credit Card and Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, Accruing	839	900
Total Accruing	850	907
Current, Non-Accruing	1	1
Total Non- Accruing	3	3
Loans and leases	853	910
Consumer | Credit Card and Other | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	8	5
Past Due, Non-Accruing	1	0
Consumer | Credit Card and Other | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	3	2
Past Due, Non-Accruing	1	2
Consumer | Credit Card and Other | Credit card
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, Accruing	272	292
Total Accruing	278	296
Current, Non-Accruing	0	0
Total Non- Accruing	0	0
Loans and leases	278	296
Consumer | Credit Card and Other | Credit card | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	3	2
Past Due, Non-Accruing	0	0
Consumer | Credit Card and Other | Credit card | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	3	2
Past Due, Non-Accruing	0	0
Consumer | Credit Card and Other | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current, Accruing	567	608
Total Accruing	572	611
Current, Non-Accruing	1	1
Total Non- Accruing	3	3
Loans and leases	575	614
Consumer | Credit Card and Other | Other | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	5	3
Past Due, Non-Accruing	1	0
Consumer | Credit Card and Other | Other | 90+ Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due, Accruing	0	0
Past Due, Non-Accruing	$ 1	$ 2