Asset Quality - Schedule of Commercial 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 commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current	9,108	8,125
Writeoff, current period	27	1
One year prior	8,143	5,489
Writeoff, one year period	14	12
Two years prior	4,711	13,088
Writeoff, two year period	18	66
Three years prior	10,162	7,693
Writeoff, three year period	36	112
Four years prior	5,812	2,905
Writeoff, four year period	34	4
Prior	9,455	8,896
Writeoff, prior	32	70
Revolving Loans Amortized Cost Basis	27,738	25,485
Writeoff, Revolving Loans Amortized Cost Basis	153	145
Revolving Loans Converted to Term Loans Amortized Cost Basis	190	210
Revolving Loans Converted to Term Loans Amortized Cost Basis, writeoff	0	0
Total	75,319	71,891
Writeoff, total	314	410
Accrued interest	351	322
Total commercial loans | Commercial and Industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Current	6,675	6,540
Writeoff, current period	8	1
One year prior	6,388	3,329
Writeoff, one year period	8	12
Two years prior	2,766	7,784
Writeoff, two year period	18	65
Three years prior	6,303	4,383
Writeoff, three year period	30	106
Four years prior	3,329	1,827
Writeoff, four year period	8	4
Prior	4,919	4,476
Writeoff, prior	21	31
Revolving Loans Amortized Cost Basis	26,262	24,412
Writeoff, Revolving Loans Amortized Cost Basis	150	144
Revolving Loans Converted to Term Loans Amortized Cost Basis	149	158
Revolving Loans Converted to Term Loans Amortized Cost Basis, writeoff	0	0
Total	56,791	52,909
Writeoff, total	243	363
Total commercial loans | Commercial and Industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current	6,584	6,345
One year prior	6,163	3,097
Two years prior	2,577	7,119
Three years prior	5,613	3,934
Four years prior	3,015	1,617
Prior	4,348	3,969
Revolving Loans Amortized Cost Basis	24,582	22,709
Revolving Loans Converted to Term Loans Amortized Cost Basis	143	115
Total	53,025	48,905
Total commercial loans | Commercial and Industrial | Criticized (Accruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	85	172
One year prior	204	219
Two years prior	172	597
Three years prior	637	419
Four years prior	291	208
Prior	563	476
Revolving Loans Amortized Cost Basis	1,556	1,550
Revolving Loans Converted to Term Loans Amortized Cost Basis	5	41
Total	3,513	3,682
Total commercial loans | Commercial and Industrial | Criticized (Nonaccruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	6	23
One year prior	21	13
Two years prior	17	68
Three years prior	53	30
Four years prior	23	2
Prior	8	31
Revolving Loans Amortized Cost Basis	124	153
Revolving Loans Converted to Term Loans Amortized Cost Basis	1	2
Total	253	322
Total commercial loans | Real estate — commercial mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Current	2,037	1,083
Writeoff, current period	19	0
One year prior	1,039	833
Writeoff, one year period	6	0
Two years prior	738	3,512
Writeoff, two year period	0	1
Three years prior	2,748	2,535
Writeoff, three year period	6	6
Four years prior	1,925	690
Writeoff, four year period	26	0
Prior	3,638	3,576
Writeoff, prior	9	32
Revolving Loans Amortized Cost Basis	1,214	1,031
Writeoff, Revolving Loans Amortized Cost Basis	3	1
Revolving Loans Converted to Term Loans Amortized Cost Basis	39	50
Revolving Loans Converted to Term Loans Amortized Cost Basis, writeoff	0	0
Total	13,378	13,310
Writeoff, total	69	40
Total commercial loans | Real estate — commercial mortgage | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current	2,015	1,052
One year prior	930	748
Two years prior	619	2,818
Three years prior	2,191	2,202
Four years prior	1,651	594
Prior	3,235	3,194
Revolving Loans Amortized Cost Basis	1,183	1,001
Revolving Loans Converted to Term Loans Amortized Cost Basis	28	41
Total	11,852	11,650
Total commercial loans | Real estate — commercial mortgage | Criticized (Accruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	22	31
One year prior	109	85
Two years prior	119	571
Three years prior	430	281
Four years prior	228	93
Prior	365	316
Revolving Loans Amortized Cost Basis	28	30
Revolving Loans Converted to Term Loans Amortized Cost Basis	11	9
Total	1,312	1,416
Total commercial loans | Real estate — commercial mortgage | Criticized (Nonaccruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0	0
One year prior	0	0
Two years prior	0	123
Three years prior	127	52
Four years prior	46	3
Prior	38	66
Revolving Loans Amortized Cost Basis	3	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	214	244
Total commercial loans | Real estate — construction
Financing Receivable, Credit Quality Indicator [Line Items]
Current	193	199
Writeoff, current period	0	0
One year prior	476	863
Writeoff, one year period	0	0
Two years prior	840	1,133
Writeoff, two year period	0	0
Three years prior	582	398
Writeoff, three year period	0	0
Four years prior	261	155
Writeoff, four year period	0	0
Prior	201	144
Writeoff, prior	0	0
Revolving Loans Amortized Cost Basis	262	42
Writeoff, Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	2	2
Revolving Loans Converted to Term Loans Amortized Cost Basis, writeoff	0	0
Total	2,817	2,936
Writeoff, total	0	0
Total commercial loans | Real estate — construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current	193	199
One year prior	476	846
Two years prior	835	1,021
Three years prior	467	340
Four years prior	219	87
Prior	73	67
Revolving Loans Amortized Cost Basis	262	42
Revolving Loans Converted to Term Loans Amortized Cost Basis	2	2
Total	2,527	2,604
Total commercial loans | Real estate — construction | Criticized (Accruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0	0
One year prior	0	17
Two years prior	5	112
Three years prior	115	58
Four years prior	42	68
Prior	128	77
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	290	332
Total commercial loans | Real estate — construction | Criticized (Nonaccruing)
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	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	203	303
Writeoff, current period	0	0
One year prior	240	464
Writeoff, one year period	0	0
Two years prior	367	659
Writeoff, two year period	0	0
Three years prior	529	377
Writeoff, three year period	0	0
Four years prior	297	233
Writeoff, four year period	0	0
Prior	697	700
Writeoff, prior	2	7
Revolving Loans Amortized Cost Basis		0
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	2,333	2,736
Writeoff, total	2	7
Total commercial loans | Commercial lease financing | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current	203	301
One year prior	238	430
Two years prior	333	626
Three years prior	514	368
Four years prior	295	217
Prior	677	679
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	2,260	2,621
Total commercial loans | Commercial lease financing | Criticized (Accruing)
Financing Receivable, Credit Quality Indicator [Line Items]
Current	0	2
One year prior	2	34
Two years prior	34	33
Three years prior	15	9
Four years prior	2	16
Prior	20	21
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	73	115
Total commercial loans | Commercial lease financing | Criticized (Nonaccruing)
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	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	$ 0	$ 0