Loans and Leases - Loans by FICO Score, Consumer (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, net of unearned income	$ 58,232	$ 31,061
Consumer real estate | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,747
2019	1,670
2018	1,093
2017	920
2016	1,054
Prior to 2016	2,821
Revolving Loans	2,055
Revolving loans converted to term loans	365
Total loans, net of unearned income	11,725
Consumer real estate | Consumer | HELOC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revolving loans converted to term loans	36
Consumer real estate | Consumer | FICO score 740 or greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,186
2019	1,167
2018	703
2017	610
2016	674
Prior to 2016	1,719
Revolving Loans	1,275
Revolving loans converted to term loans	159
Total loans, net of unearned income	7,493
Consumer real estate | Consumer | FICO score 720-739
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	157
2019	158
2018	100
2017	77
2016	92
Prior to 2016	197
Revolving Loans	186
Revolving loans converted to term loans	29
Total loans, net of unearned income	996
Consumer real estate | Consumer | FICO score 700-719
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	122
2019	107
2018	78
2017	76
2016	73
Prior to 2016	221
Revolving Loans	177
Revolving loans converted to term loans	34
Total loans, net of unearned income	888
Consumer real estate | Consumer | FICO score 660-699
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	130
2019	141
2018	123
2017	75
2016	85
Prior to 2016	296
Revolving Loans	264
Revolving loans converted to term loans	59
Total loans, net of unearned income	1,173
Consumer real estate | Consumer | FICO score 620-659
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	45
2019	61
2018	37
2017	28
2016	35
Prior to 2016	127
Revolving Loans	92
Revolving loans converted to term loans	36
Total loans, net of unearned income	461
Consumer real estate | Consumer | FICO score less than 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	107
2019	36
2018	52
2017	54
2016	95
Prior to 2016	261
Revolving Loans	61
Revolving loans converted to term loans	48
Total loans, net of unearned income	714
Credit card and other | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	122
2019	91
2018	107
2017	78
2016	63
Prior to 2016	279
Revolving Loans	373
Revolving loans converted to term loans	15
Total loans, net of unearned income	1,128
Credit card and other | Consumer | FICO score 740 or greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	57
2019	52
2018	59
2017	37
2016	23
Prior to 2016	116
Revolving Loans	159
Revolving loans converted to term loans	5
Total loans, net of unearned income	508
Credit card and other | Consumer | FICO score 720-739
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	7
2019	7
2018	9
2017	8
2016	8
Prior to 2016	27
Revolving Loans	91
Revolving loans converted to term loans	2
Total loans, net of unearned income	159
Credit card and other | Consumer | FICO score 700-719
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	9
2019	8
2018	9
2017	8
2016	4
Prior to 2016	38
Revolving Loans	37
Revolving loans converted to term loans	3
Total loans, net of unearned income	116
Credit card and other | Consumer | FICO score 660-699
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	30
2019	12
2018	15
2017	9
2016	9
Prior to 2016	48
Revolving Loans	46
Revolving loans converted to term loans	3
Total loans, net of unearned income	172
Credit card and other | Consumer | FICO score 620-659
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	5
2019	5
2018	7
2017	5
2016	10
Prior to 2016	24
Revolving Loans	20
Revolving loans converted to term loans	1
Total loans, net of unearned income	77
Credit card and other | Consumer | FICO score less than 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	14
2019	7
2018	8
2017	11
2016	9
Prior to 2016	26
Revolving Loans	20
Revolving loans converted to term loans	1
Total loans, net of unearned income	$ 96