Asset Quality - Schedule of Consumer Credit Exposure (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 105,902	$ 104,260
Accrued interest	472	456
Total consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current	603	628
Writeoff, current year	3	1
One year prior	513	1,140
Writeoff, one year	4	7
Two years prior	1,012	8,104
Writeoff, two year	6	18
Three years prior	7,551	10,471
Writeoff, three year	6	12
Four years prior	9,788	3,934
Writeoff, four year	6	7
Prior	6,564	3,328
Writeoff, prior	7	8
Revolving Loans Amortized Cost Basis	4,272	4,408
Writeoff, Revolving Loans Amortized Cost Basis	47	63
Revolving Loans Converted to Term Loans Amortized Cost Basis	280	356
Revolving Loans Converted to Term Loans Amortized Cost Basis, writeoff	0	0
Total	30,583	32,369
Writeoff, total	79	116
Accrued interest	121	134
Total consumer loans | Real estate — residential mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Current	304	355
Writeoff, current year	0	1
One year prior	311	800
Writeoff, one year	0	0
Two years prior	745	6,399
Writeoff, two year	0	1
Three years prior	6,043	7,921
Writeoff, three year	0	0
Four years prior	7,514	2,471
Writeoff, four year	0	0
Prior	4,089	1,939
Writeoff, prior	1	1
Revolving Loans Amortized Cost Basis	2	1
Writeoff, Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis, writeoff	0	0
Total	19,008	19,886
Writeoff, total	1	3
Total consumer loans | Real estate — residential mortgage | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
Current	256	281
One year prior	260	669
Two years prior	638	5,720
Three years prior	5,427	7,203
Four years prior	6,846	2,247
Prior	3,482	1,510
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	16,909	17,630
Total consumer loans | Real estate — residential mortgage | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
Current	44	67
One year prior	38	116
Two years prior	84	597
Three years prior	531	655
Four years prior	603	199
Prior	448	280
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	1,748	1,914
Total consumer loans | Real estate — residential mortgage | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
Current	2	4
One year prior	10	13
Two years prior	21	81
Three years prior	84	63
Four years prior	65	24
Prior	149	134
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	331	319
Total consumer loans | Real estate — residential mortgage | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
Current	2	3
One year prior	3	2
Two years prior	2	1
Three years prior	1	0
Four years prior	0	1
Prior	10	15
Revolving Loans Amortized Cost Basis	2	1
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	20	23
Total consumer loans | Home equity loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current	49	52
Writeoff, current year	0	0
One year prior	44	53
Writeoff, one year	0	0
Two years prior	44	204
Writeoff, two year	0	0
Three years prior	181	996
Writeoff, three year	0	0
Four years prior	902	772
Writeoff, four year	0	0
Prior	1,594	1,000
Writeoff, prior	0	1
Revolving Loans Amortized Cost Basis	2,769	2,925
Writeoff, Revolving Loans Amortized Cost Basis	1	1
Revolving Loans Converted to Term Loans Amortized Cost Basis	280	356
Revolving Loans Converted to Term Loans Amortized Cost Basis, writeoff	0	0
Total	5,863	6,358
Writeoff, total	1	2
Total consumer loans | Home equity loans | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
Current	35	33
One year prior	27	31
Two years prior	25	139
Three years prior	121	775
Four years prior	701	612
Prior	1,217	731
Revolving Loans Amortized Cost Basis	1,783	1,886
Revolving Loans Converted to Term Loans Amortized Cost Basis	195	251
Total	4,104	4,458
Total consumer loans | Home equity loans | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
Current	13	17
One year prior	15	17
Two years prior	14	50
Three years prior	45	181
Four years prior	158	129
Prior	269	186
Revolving Loans Amortized Cost Basis	732	772
Revolving Loans Converted to Term Loans Amortized Cost Basis	62	80
Total	1,308	1,432
Total consumer loans | Home equity loans | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
Current	1	2
One year prior	2	5
Two years prior	5	15
Three years prior	15	40
Four years prior	43	31
Prior	107	82
Revolving Loans Amortized Cost Basis	248	263
Revolving Loans Converted to Term Loans Amortized Cost Basis	23	25
Total	444	463
Total consumer loans | Home equity loans | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0	0
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Prior	1	1
Revolving Loans Amortized Cost Basis	6	4
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	7	5
Total consumer loans | Other consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current	250	221
Writeoff, current year	3	0
One year prior	158	287
Writeoff, one year	4	7
Two years prior	223	1,501
Writeoff, two year	6	17
Three years prior	1,327	1,554
Writeoff, three year	6	12
Four years prior	1,372	691
Writeoff, four year	6	7
Prior	881	389
Writeoff, prior	6	6
Revolving Loans Amortized Cost Basis	568	524
Writeoff, Revolving Loans Amortized Cost Basis	11	15
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis, writeoff	0	0
Total	4,779	5,167
Writeoff, total	42	64
Total consumer loans | Other consumer loans | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
Current	137	107
One year prior	80	143
Two years prior	112	1,149
Three years prior	1,024	1,210
Four years prior	1,076	527
Prior	635	245
Revolving Loans Amortized Cost Basis	83	88
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	3,147	3,469
Total consumer loans | Other consumer loans | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
Current	86	70
One year prior	54	109
Two years prior	82	275
Three years prior	234	268
Four years prior	228	128
Prior	188	108
Revolving Loans Amortized Cost Basis	175	184
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	1,047	1,142
Total consumer loans | Other consumer loans | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
Current	10	9
One year prior	12	23
Two years prior	23	59
Three years prior	57	59
Four years prior	55	29
Prior	50	24
Revolving Loans Amortized Cost Basis	53	56
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	260	259
Total consumer loans | Other consumer loans | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
Current	17	35
One year prior	12	12
Two years prior	6	18
Three years prior	12	17
Four years prior	13	7
Prior	8	12
Revolving Loans Amortized Cost Basis	257	196
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	325	297
Total consumer loans | Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0	0
Writeoff, current year	0	0
One year prior	0	0
Writeoff, one year	0	0
Two years prior	0	0
Writeoff, two year	0	0
Three years prior	0	0
Writeoff, three year	0	0
Four years prior	0	0
Writeoff, four year	0	0
Prior	0	0
Writeoff, prior	0	0
Revolving Loans Amortized Cost Basis	933	958
Writeoff, Revolving Loans Amortized Cost Basis	35	47
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis, writeoff	0	0
Total	933	958
Writeoff, total	35	47
Total consumer loans | Credit cards | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0	0
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	460	476
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	460	476
Total consumer loans | Credit cards | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0	0
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	366	372
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	366	372
Total consumer loans | Credit cards | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0	0
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	106	109
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	106	109
Total consumer loans | Credit cards | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0	0
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four 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