Asset Quality - Consumer 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 consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	8,343	13,637
Two years prior	12,918	5,890
Three years prior	5,084	2,095
Four years prior	1,636	432
Five years prior	328	384
Prior	2,604	2,812
Revolving Loans Amortized Cost Basis	5,111	5,156
Revolving Loans Converted to Term Loans Amortized Cost Basis	570	612
Total	36,594	31,018
Accrued interest	77	85
Total consumer loans | Real estate — residential mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	6,301	9,636
Two years prior	9,266	3,274
Three years prior	2,942	966
Four years prior	774	140
Five years prior	111	163
Prior	1,443	1,576
Revolving Loans Amortized Cost Basis	1	1
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	20,838	15,756
Total consumer loans | Real estate — residential mortgage | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	4,959	7,906
Two years prior	8,248	2,909
Three years prior	2,624	777
Four years prior	643	84
Five years prior	63	126
Prior	1,015	1,096
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	17,552	12,898
Total consumer loans | Real estate — residential mortgage | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	1,256	1,686
Two years prior	979	351
Three years prior	299	169
Four years prior	115	39
Five years prior	32	25
Prior	261	308
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	2,942	2,578
Total consumer loans | Real estate — residential mortgage | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	35	26
Two years prior	38	14
Three years prior	18	19
Four years prior	15	16
Five years prior	15	9
Prior	139	142
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	260	226
Total consumer loans | Real estate — residential mortgage | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	51	18
Two years prior	1	0
Three years prior	1	1
Four years prior	1	1
Five years prior	1	3
Prior	28	30
Revolving Loans Amortized Cost Basis	1	1
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	84	54
Total consumer loans | Home equity loans
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	236	1,472
Two years prior	1,212	1,119
Three years prior	986	382
Four years prior	314	153
Five years prior	119	181
Prior	929	964
Revolving Loans Amortized Cost Basis	3,560	3,584
Revolving Loans Converted to Term Loans Amortized Cost Basis	570	612
Total	7,926	8,467
Total consumer loans | Home equity loans | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	138	1,051
Two years prior	879	830
Three years prior	760	251
Four years prior	214	96
Five years prior	76	128
Prior	647	666
Revolving Loans Amortized Cost Basis	2,303	2,244
Revolving Loans Converted to Term Loans Amortized Cost Basis	403	423
Total	5,420	5,689
Total consumer loans | Home equity loans | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	85	394
Two years prior	302	263
Three years prior	204	111
Four years prior	83	44
Five years prior	33	40
Prior	196	204
Revolving Loans Amortized Cost Basis	961	1,004
Revolving Loans Converted to Term Loans Amortized Cost Basis	129	143
Total	1,993	2,203
Total consumer loans | Home equity loans | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	9	27
Two years prior	31	24
Three years prior	22	20
Four years prior	17	13
Five years prior	10	13
Prior	84	92
Revolving Loans Amortized Cost Basis	294	333
Revolving Loans Converted to Term Loans Amortized Cost Basis	38	46
Total	505	568
Total consumer loans | Home equity loans | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	4	0
Two years prior	0	2
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	2	2
Revolving Loans Amortized Cost Basis	2	3
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	8	7
Total consumer loans | Consumer direct loans
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	1,806	2,524
Two years prior	2,438	1,497
Three years prior	1,156	747
Four years prior	548	139
Five years prior	98	40
Prior	184	207
Revolving Loans Amortized Cost Basis	573	599
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	6,803	5,753
Total consumer loans | Consumer direct loans | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	1,229	1,799
Two years prior	1,876	1,129
Three years prior	860	517
Four years prior	378	65
Five years prior	50	17
Prior	106	129
Revolving Loans Amortized Cost Basis	104	109
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	4,603	3,765
Total consumer loans | Consumer direct loans | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	474	612
Two years prior	461	295
Three years prior	242	174
Four years prior	129	46
Five years prior	29	10
Prior	44	45
Revolving Loans Amortized Cost Basis	204	212
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	1,583	1,394
Total consumer loans | Consumer direct loans | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	44	45
Two years prior	62	33
Three years prior	31	27
Four years prior	23	11
Five years prior	7	3
Prior	10	12
Revolving Loans Amortized Cost Basis	55	60
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	232	191
Total consumer loans | Consumer direct loans | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	59	68
Two years prior	39	40
Three years prior	23	29
Four years prior	18	17
Five years prior	12	10
Prior	24	21
Revolving Loans Amortized Cost Basis	210	218
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	385	403
Total consumer loans | Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	977	972
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	977	972
Total consumer loans | Credit cards | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	493	500
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	493	500
Total consumer loans | Credit cards | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	391	387
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	391	387
Total consumer loans | Credit cards | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	92	84
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	92	84
Total consumer loans | Credit cards | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	1	1
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	1	1
Total consumer loans | Consumer indirect loans
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	5
Two years prior	2	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	48	65
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	50	70
Total consumer loans | Consumer indirect loans | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	5
Two years prior	2	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	24	30
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	26	35
Total consumer loans | Consumer indirect loans | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	17	26
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	17	26
Total consumer loans | Consumer indirect loans | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	7	9
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	7	9
Total consumer loans | Consumer indirect loans | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	$ 0	$ 0