Loans and Leases - Loans by FICO Score (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 55,012	$ 54,859
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]
Financing receivable, originated year one	718	2,205
Financing receivable, originated year two	2,694	1,690
Financing receivable, originated year three	1,334	1,232
Financing receivable, originated year four	935	763
Financing receivable, originated year five	547	585
Financing receivable, originated prior to year five	2,752	2,333
Revolving Loans	1,635	1,701
Revolving Loans converted to term loans	259	263
Loans and leases	10,874	10,772
Consumer | Consumer real estate | FICO score 740 or greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	493	1,594
Financing receivable, originated year two	2,004	1,156
Financing receivable, originated year three	944	825
Financing receivable, originated year four	657	473
Financing receivable, originated year five	384	394
Financing receivable, originated prior to year five	1,885	1,335
Revolving Loans	1,207	1,086
Revolving Loans converted to term loans	112	115
Loans and leases	7,686	6,978
Consumer | Consumer real estate | FICO score 720-739
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	101	236
Financing receivable, originated year two	268	171
Financing receivable, originated year three	137	109
Financing receivable, originated year four	83	61
Financing receivable, originated year five	45	44
Financing receivable, originated prior to year five	212	209
Revolving Loans	136	162
Revolving Loans converted to term loans	24	21
Loans and leases	1,006	1,013
Consumer | Consumer real estate | FICO score 700-719
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	21	143
Financing receivable, originated year two	167	112
Financing receivable, originated year three	83	81
Financing receivable, originated year four	56	68
Financing receivable, originated year five	32	45
Financing receivable, originated prior to year five	168	153
Revolving Loans	100	141
Revolving Loans converted to term loans	25	23
Loans and leases	652	766
Consumer | Consumer real estate | FICO score 660-699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	91	164
Financing receivable, originated year two	197	131
Financing receivable, originated year three	109	120
Financing receivable, originated year four	95	106
Financing receivable, originated year five	58	44
Financing receivable, originated prior to year five	224	246
Revolving Loans	121	204
Revolving Loans converted to term loans	41	44
Loans and leases	936	1,059
Consumer | Consumer real estate | FICO score 620-659
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	11	42
Financing receivable, originated year two	44	36
Financing receivable, originated year three	35	55
Financing receivable, originated year four	25	23
Financing receivable, originated year five	14	13
Financing receivable, originated prior to year five	135	118
Revolving Loans	37	66
Revolving Loans converted to term loans	26	27
Loans and leases	327	380
Consumer | Consumer real estate | FICO score less than 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	1	26
Financing receivable, originated year two	14	84
Financing receivable, originated year three	26	42
Financing receivable, originated year four	19	32
Financing receivable, originated year five	14	45
Financing receivable, originated prior to year five	128	272
Revolving Loans	34	42
Revolving Loans converted to term loans	31	33
Loans and leases	267	576
Consumer | Credit Card and Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	15	131
Financing receivable, originated year two	92	57
Financing receivable, originated year three	48	47
Financing receivable, originated year four	46	44
Financing receivable, originated year five	37	31
Financing receivable, originated prior to year five	140	155
Revolving Loans	447	426
Revolving Loans converted to term loans	28	19
Loans and leases	853	910
Revolving loans converted to term loan during period	2	9
Consumer | Credit Card and Other | FICO score 740 or greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	10	56
Financing receivable, originated year two	61	35
Financing receivable, originated year three	34	29
Financing receivable, originated year four	33	23
Financing receivable, originated year five	26	13
Financing receivable, originated prior to year five	89	56
Revolving Loans	231	200
Revolving Loans converted to term loans	17	11
Loans and leases	501	423
Consumer | Credit Card and Other | FICO score 720-739
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	2	14
Financing receivable, originated year two	12	5
Financing receivable, originated year three	3	4
Financing receivable, originated year four	4	3
Financing receivable, originated year five	2	4
Financing receivable, originated prior to year five	8	17
Revolving Loans	39	46
Revolving Loans converted to term loans	3	3
Loans and leases	73	96
Consumer | Credit Card and Other | FICO score 700-719
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	1	8
Financing receivable, originated year two	5	5
Financing receivable, originated year three	4	4
Financing receivable, originated year four	3	4
Financing receivable, originated year five	2	3
Financing receivable, originated prior to year five	7	17
Revolving Loans	34	42
Revolving Loans converted to term loans	2	1
Loans and leases	58	84
Consumer | Credit Card and Other | FICO score 660-699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	1	25
Financing receivable, originated year two	8	6
Financing receivable, originated year three	4	5
Financing receivable, originated year four	4	6
Financing receivable, originated year five	4	4
Financing receivable, originated prior to year five	13	31
Revolving Loans	115	98
Revolving Loans converted to term loans	3	2
Loans and leases	152	177
Consumer | Credit Card and Other | FICO score 620-659
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	1	4
Financing receivable, originated year two	3	3
Financing receivable, originated year three	2	2
Financing receivable, originated year four	1	4
Financing receivable, originated year five	2	3
Financing receivable, originated prior to year five	10	18
Revolving Loans	15	22
Revolving Loans converted to term loans	2	1
Loans and leases	36	57
Consumer | Credit Card and Other | FICO score less than 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	0	24
Financing receivable, originated year two	3	3
Financing receivable, originated year three	1	3
Financing receivable, originated year four	1	4
Financing receivable, originated year five	1	4
Financing receivable, originated prior to year five	13	16
Revolving Loans	13	18
Revolving Loans converted to term loans	1	1
Loans and leases	33	73
HELOC | Consumer | Consumer real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	1,894	1,964
Revolving loans converted to term loan during period	$ 5	$ 43