Loans and Leases - Loans by FICO Score (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 61,778	$ 58,102
Consumer:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	13,685	12,253
Consumer: | Consumer real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	1,920	2,938
Financing receivable, originated year two	2,868	2,479
Financing receivable, originated year three	2,336	1,175
Financing receivable, originated year four	1,072	784
Financing receivable, originated year five	719	452
Financing receivable, originated prior to year five	2,522	2,397
Revolving Loans	2,123	1,877
Revolving Loans Converted to Term Loans	125	151
Loans and leases	13,685	12,253
Consumer: | Consumer real estate | FICO score 740 or greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	1,425	2,154
Financing receivable, originated year two	2,110	1,847
Financing receivable, originated year three	1,750	819
Financing receivable, originated year four	748	523
Financing receivable, originated year five	475	278
Financing receivable, originated prior to year five	1,398	1,294
Revolving Loans	1,542	1,297
Revolving Loans Converted to Term Loans	53	63
Loans and leases	9,501	8,275
Consumer: | Consumer real estate | FICO score 720-739
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	180	292
Financing receivable, originated year two	287	246
Financing receivable, originated year three	230	116
Financing receivable, originated year four	110	98
Financing receivable, originated year five	90	34
Financing receivable, originated prior to year five	239	238
Revolving Loans	189	183
Revolving Loans Converted to Term Loans	16	18
Loans and leases	1,341	1,225
Consumer: | Consumer real estate | FICO score 700-719
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	132	242
Financing receivable, originated year two	234	206
Financing receivable, originated year three	195	93
Financing receivable, originated year four	87	55
Financing receivable, originated year five	52	35
Financing receivable, originated prior to year five	230	226
Revolving Loans	157	142
Revolving Loans Converted to Term Loans	18	22
Loans and leases	1,105	1,021
Consumer: | Consumer real estate | FICO score 660-699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	162	214
Financing receivable, originated year two	200	137
Financing receivable, originated year three	119	90
Financing receivable, originated year four	83	55
Financing receivable, originated year five	53	62
Financing receivable, originated prior to year five	303	278
Revolving Loans	175	192
Revolving Loans Converted to Term Loans	19	23
Loans and leases	1,114	1,051
Consumer: | Consumer real estate | FICO score 620-659
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	9	21
Financing receivable, originated year two	20	24
Financing receivable, originated year three	23	25
Financing receivable, originated year four	24	41
Financing receivable, originated year five	37	20
Financing receivable, originated prior to year five	112	105
Revolving Loans	37	47
Revolving Loans Converted to Term Loans	7	9
Loans and leases	269	292
Consumer: | Consumer real estate | FICO score less than 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	12	15
Financing receivable, originated year two	17	19
Financing receivable, originated year three	19	32
Financing receivable, originated year four	20	12
Financing receivable, originated year five	12	23
Financing receivable, originated prior to year five	240	256
Revolving Loans	23	16
Revolving Loans Converted to Term Loans	12	16
Loans and leases	355	389
Consumer: | Credit Card and Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	64	53
Financing receivable, originated year two	48	30
Financing receivable, originated year three	27	21
Financing receivable, originated year four	17	23
Financing receivable, originated year five	20	13
Financing receivable, originated prior to year five	162	114
Revolving Loans	460	576
Revolving Loans Converted to Term Loans	11	10
Loans and leases	809	840
Consumer: | Credit Card and Other | FICO score 740 or greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	43	36
Financing receivable, originated year two	29	14
Financing receivable, originated year three	13	10
Financing receivable, originated year four	6	10
Financing receivable, originated year five	4	4
Financing receivable, originated prior to year five	34	25
Revolving Loans	223	291
Revolving Loans Converted to Term Loans	5	6
Loans and leases	357	396
Consumer: | Credit Card and Other | FICO score 720-739
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	5	3
Financing receivable, originated year two	3	2
Financing receivable, originated year three	2	2
Financing receivable, originated year four	1	1
Financing receivable, originated year five	1	0
Financing receivable, originated prior to year five	5	4
Revolving Loans	27	30
Revolving Loans Converted to Term Loans	1	1
Loans and leases	45	43
Consumer: | Credit Card and Other | FICO score 700-719
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	4	3
Financing receivable, originated year two	3	3
Financing receivable, originated year three	4	1
Financing receivable, originated year four	1	1
Financing receivable, originated year five	1	0
Financing receivable, originated prior to year five	5	4
Revolving Loans	23	33
Revolving Loans Converted to Term Loans	3	1
Loans and leases	44	46
Consumer: | Credit Card and Other | FICO score 660-699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	2	3
Financing receivable, originated year two	3	2
Financing receivable, originated year three	1	1
Financing receivable, originated year four	1	1
Financing receivable, originated year five	1	2
Financing receivable, originated prior to year five	8	7
Revolving Loans	19	30
Revolving Loans Converted to Term Loans	1	1
Loans and leases	36	47
Consumer: | Credit Card and Other | FICO score 620-659
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	1	1
Financing receivable, originated year two	1	3
Financing receivable, originated year three	1	1
Financing receivable, originated year four	0	0
Financing receivable, originated year five	0	0
Financing receivable, originated prior to year five	3	3
Revolving Loans	6	18
Revolving Loans Converted to Term Loans	0	0
Loans and leases	12	26
Consumer: | Credit Card and Other | FICO score less than 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	9	7
Financing receivable, originated year two	9	6
Financing receivable, originated year three	6	6
Financing receivable, originated year four	8	10
Financing receivable, originated year five	13	7
Financing receivable, originated prior to year five	107	71
Revolving Loans	162	174
Revolving Loans Converted to Term Loans	1	1
Loans and leases	$ 315	$ 282