Asset Quality - Commercial Credit Exposure (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 116,191	$ 101,854
Accrued interest	274	198
Total commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current	12,957
One year prior	15,843	18,212
Two years prior	5,996	7,556
Three years prior	6,282	7,624
Four years prior	3,463	4,772
Five years prior		3,136
Prior	8,124
Prior		7,235
Revolving Loans Amortized Cost Basis	26,719	22,159
Revolving Loans Converted to Term Loans Amortized Cost Basis	213	142
Total	79,597	70,836
Accrued interest	197	113
Total commercial loans | Commercial and Industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current	7,622
One year prior	9,938	11,740
Two years prior	3,866	5,013
Three years prior	3,387	4,176
Four years prior	2,148	2,956
Five years prior		1,996
Prior	4,107
Prior		3,244
Revolving Loans Amortized Cost Basis	25,741	21,312
Revolving Loans Converted to Term Loans Amortized Cost Basis	162	88
Total	56,971	50,525
Total commercial loans | Commercial and Industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current	7,572
One year prior	9,757	11,675
Two years prior	3,729	4,941
Three years prior	3,267	4,040
Four years prior	1,862	2,771
Five years prior		1,777
Prior	3,831
Prior		3,108
Revolving Loans Amortized Cost Basis	24,796	20,406
Revolving Loans Converted to Term Loans Amortized Cost Basis	132	72
Total	54,946	48,790
Total commercial loans | Commercial and Industrial | Criticized (Accruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	11
One year prior	179	64
Two years prior	130	71
Three years prior	114	115
Four years prior	278	175
Five years prior		200
Prior	251
Prior		121
Revolving Loans Amortized Cost Basis	865	784
Revolving Loans Converted to Term Loans Amortized Cost Basis	28	14
Total	1,856	1,544
Total commercial loans | Commercial and Industrial | Criticized (Nonaccruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	39
One year prior	2	1
Two years prior	7	1
Three years prior	6	21
Four years prior	8	10
Five years prior		19
Prior	25
Prior		15
Revolving Loans Amortized Cost Basis	80	122
Revolving Loans Converted to Term Loans Amortized Cost Basis	2	2
Total	169	191
Total commercial loans | Commercial mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Current	4,162
One year prior	4,288	4,938
Two years prior	1,041	1,220
Three years prior	1,999	2,208
Four years prior	920	1,235
Five years prior		721
Prior	2,962
Prior		3,024
Revolving Loans Amortized Cost Basis	977	844
Revolving Loans Converted to Term Loans Amortized Cost Basis	51	54
Total	16,400	14,244
Total commercial loans | Commercial mortgage | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current	4,162
One year prior	4,264	4,923
Two years prior	1,014	1,197
Three years prior	1,912	2,137
Four years prior	827	1,168
Five years prior		612
Prior	2,695
Prior		2,787
Revolving Loans Amortized Cost Basis	927	803
Revolving Loans Converted to Term Loans Amortized Cost Basis	50	53
Total	15,851	13,680
Total commercial loans | Commercial mortgage | Criticized (Accruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0
One year prior	24	15
Two years prior	26	22
Three years prior	85	70
Four years prior	91	62
Five years prior		109
Prior	242
Prior		206
Revolving Loans Amortized Cost Basis	46	35
Revolving Loans Converted to Term Loans Amortized Cost Basis	1	1
Total	515	520
Total commercial loans | Commercial mortgage | Criticized (Nonaccruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0
One year prior	0	0
Two years prior	1	1
Three years prior	2	1
Four years prior	2	5
Five years prior		0
Prior	25
Prior		31
Revolving Loans Amortized Cost Basis	4	6
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	34	44
Total commercial loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current	475
One year prior	747	495
Two years prior	521	569
Three years prior	370	535
Four years prior	182	266
Five years prior		96
Prior	53
Prior		32
Revolving Loans Amortized Cost Basis	1	3
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	2,349	1,996
Total commercial loans | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current	475
One year prior	747	495
Two years prior	516	565
Three years prior	365	530
Four years prior	168	223
Five years prior		92
Prior	49
Prior		32
Revolving Loans Amortized Cost Basis	1	2
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	2,321	1,939
Total commercial loans | Construction | Criticized (Accruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0
One year prior	0	0
Two years prior	5	4
Three years prior	5	5
Four years prior	14	43
Five years prior		4
Prior	4
Prior		0
Revolving Loans Amortized Cost Basis	0	1
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	28	57
Total commercial loans | Construction | Criticized (Nonaccruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior		0
Prior	0
Prior		0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	0	0
Total commercial loans | Commercial lease financing
Financing Receivable, Credit Quality Indicator [Line Items]
Current	698
One year prior	870	1,039
Two years prior	568	754
Three years prior	526	705
Four years prior	213	315
Five years prior		323
Prior	1,002
Prior		935
Revolving Loans Amortized Cost Basis		0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	3,877	4,071
Total commercial loans | Commercial lease financing | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current	697
One year prior	869	1,039
Two years prior	558	748
Three years prior	506	675
Four years prior	199	301
Five years prior		309
Prior	991
Prior		927
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	3,820	3,999
Total commercial loans | Commercial lease financing | Criticized (Accruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	1
One year prior	1	0
Two years prior	10	6
Three years prior	19	29
Four years prior	13	13
Five years prior		13
Prior	11
Prior		7
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	55	68
Total commercial loans | Commercial lease financing | Criticized (Nonaccruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0
One year prior	0	0
Two years prior	0	0
Three years prior	1	1
Four years prior	1	1
Five years prior		1
Prior	0
Prior		1
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	$ 2	$ 4