Loans - Wholesale Loan Portfolio, Internal Risk Ratings and Gross Charge-offs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	$ 1,408,905	$ 1,299,590	$ 1,280,870
Loans by origination year
Total retained loans	1,408,905	1,299,590	1,280,870
Gross charge-offs by origination year
Total gross charge-offs	12,040	10,519	7,653
Wholesale
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	$ 792,367	$ 690,396	672,472
% of investment-grade to total retained loans	68.32%	68.32%
% of total criticized to total retained loans	3.63%	3.67%
% of criticized nonaccrual to total retained loans	0.56%	0.57%
Loans by origination year
Total retained loans	$ 792,367	$ 690,396	672,472
Gross charge-offs by origination year
Total gross charge-offs	1,787	1,022	$ 1,011
Wholesale | Investment-grade
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	541,364	471,670
Loans by origination year
Total retained loans	541,364	471,670
Wholesale | Total noninvestment-grade
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	251,003	218,726
Loans by origination year
Total retained loans	251,003	218,726
Wholesale | Noncriticized
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	222,249	193,356
Loans by origination year
Total retained loans	222,249	193,356
Wholesale | Criticized performing
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	24,356	21,428
Loans by origination year
Total retained loans	24,356	21,428
Wholesale | Criticized nonaccrual
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	4,398	3,942
Loans by origination year
Total retained loans	4,398	3,942
Wholesale | Secured by real estate
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	$ 165,545	$ 162,432
% of investment-grade to total retained loans	71.81%	70.36%
% of total criticized to total retained loans	6.37%	6.61%
% of criticized nonaccrual to total retained loans	1.01%	0.89%
Loans by origination year
Term loans originated in 2025/2024	$ 24,172	$ 14,240
Term loans originated in 2024/2023	12,472	15,200
Term loans originated in 2023/2022	13,579	40,001
Term loans originated in 2022/2021	34,916	31,363
Term loans originated in 2021/2020	28,644	19,010
Term loans originated prior to 2021/2020	48,370	39,880
Revolving loans within revolving period	3,299	2,645
Revolving loans converted to term loans	93	93
Total retained loans	165,545	162,432
Gross charge-offs by origination year
Gross charge-offs originated in 2025/2024	0	72
Gross charge-offs originated in 2024/2023	54	18
Gross charge-offs originated in 2023/2022	13	43
Gross charge-offs originated in 2022/2021	92	2
Gross charge-offs originated in 2021/2020	119	109
Gross charge-offs originated prior to 2021/2020	141	80
Gross charge-offs originated within the revolving period	1	0
Gross charge-offs originated converted to term loans	0	0
Total gross charge-offs	420	324
Wholesale | Secured by real estate | Investment-grade
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	118,875	114,280
Loans by origination year
Term loans originated in 2025/2024	17,242	10,002
Term loans originated in 2024/2023	9,440	9,834
Term loans originated in 2023/2022	9,187	25,284
Term loans originated in 2022/2021	22,472	22,796
Term loans originated in 2021/2020	22,019	15,548
Term loans originated prior to 2021/2020	37,392	29,488
Revolving loans within revolving period	1,123	1,328
Revolving loans converted to term loans	0	0
Total retained loans	118,875	114,280
Wholesale | Secured by real estate | Total noninvestment-grade
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	46,670	48,152
Loans by origination year
Term loans originated in 2025/2024	6,930	4,238
Term loans originated in 2024/2023	3,032	5,366
Term loans originated in 2023/2022	4,392	14,717
Term loans originated in 2022/2021	12,444	8,567
Term loans originated in 2021/2020	6,625	3,462
Term loans originated prior to 2021/2020	10,978	10,392
Revolving loans within revolving period	2,176	1,317
Revolving loans converted to term loans	93	93
Total retained loans	46,670	48,152
Wholesale | Secured by real estate | Noncriticized
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	36,120	37,422
Loans by origination year
Total retained loans	36,120	37,422
Wholesale | Secured by real estate | Criticized performing
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	8,872	9,291
Loans by origination year
Total retained loans	8,872	9,291
Wholesale | Secured by real estate | Criticized nonaccrual
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	$ 1,678	$ 1,439
% of criticized nonaccrual to total retained loans	1.01%	0.89%
Loans by origination year
Total retained loans	$ 1,678	$ 1,439
Wholesale | Commercial and industrial
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	$ 174,403	$ 166,790
% of investment-grade to total retained loans	38.38%	42.49%
% of total criticized to total retained loans	8.37%	7.64%
% of criticized nonaccrual to total retained loans	1.12%	1.06%
Loans by origination year
Term loans originated in 2025/2024	$ 49,092	$ 32,815
Term loans originated in 2024/2023	18,794	17,635
Term loans originated in 2023/2022	8,967	17,530
Term loans originated in 2022/2021	9,952	8,441
Term loans originated in 2021/2020	3,842	1,850
Term loans originated prior to 2021/2020	2,050	2,114
Revolving loans within revolving period	81,605	86,280
Revolving loans converted to term loans	101	125
Total retained loans	174,403	166,790
Gross charge-offs by origination year
Gross charge-offs originated in 2025/2024	43	25
Gross charge-offs originated in 2024/2023	64	22
Gross charge-offs originated in 2023/2022	11	128
Gross charge-offs originated in 2022/2021	151	24
Gross charge-offs originated in 2021/2020	129	1
Gross charge-offs originated prior to 2021/2020	26	50
Gross charge-offs originated within the revolving period	461	270
Gross charge-offs originated converted to term loans	8	5
Total gross charge-offs	893	525
Wholesale | Commercial and industrial | Investment-grade
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	66,942	70,862
Loans by origination year
Term loans originated in 2025/2024	16,186	11,564
Term loans originated in 2024/2023	5,418	6,285
Term loans originated in 2023/2022	3,040	6,588
Term loans originated in 2022/2021	4,352	3,119
Term loans originated in 2021/2020	1,836	1,067
Term loans originated prior to 2021/2020	1,225	1,139
Revolving loans within revolving period	34,884	41,099
Revolving loans converted to term loans	1	1
Total retained loans	66,942	70,862
Wholesale | Commercial and industrial | Total noninvestment-grade
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	107,461	95,928
Loans by origination year
Term loans originated in 2025/2024	32,906	21,251
Term loans originated in 2024/2023	13,376	11,350
Term loans originated in 2023/2022	5,927	10,942
Term loans originated in 2022/2021	5,600	5,322
Term loans originated in 2021/2020	2,006	783
Term loans originated prior to 2021/2020	825	975
Revolving loans within revolving period	46,721	45,181
Revolving loans converted to term loans	100	124
Total retained loans	107,461	95,928
Wholesale | Commercial and industrial | Noncriticized
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	92,856	83,191
Loans by origination year
Total retained loans	92,856	83,191
Wholesale | Commercial and industrial | Criticized performing
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	12,651	10,977
Loans by origination year
Total retained loans	12,651	10,977
Wholesale | Commercial and industrial | Criticized nonaccrual
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	1,954	1,760
Loans by origination year
Total retained loans	1,954	1,760
Wholesale | Other
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	$ 452,419	$ 361,174
% of investment-grade to total retained loans	78.59%	79.33%
% of total criticized to total retained loans	0.80%	0.53%
% of criticized nonaccrual to total retained loans	0.17%	0.21%
Loans by origination year
Term loans originated in 2025/2024	$ 59,235	$ 42,268
Term loans originated in 2024/2023	19,579	24,287
Term loans originated in 2023/2022	12,364	19,190
Term loans originated in 2022/2021	14,917	9,584
Term loans originated in 2021/2020	7,587	9,998
Term loans originated prior to 2021/2020	14,320	9,268
Revolving loans within revolving period	324,245	244,903
Revolving loans converted to term loans	172	1,676
Total retained loans	452,419	361,174
Gross charge-offs by origination year
Gross charge-offs originated in 2025/2024	46	0
Gross charge-offs originated in 2024/2023	195	38
Gross charge-offs originated in 2023/2022	32	3
Gross charge-offs originated in 2022/2021	2	36
Gross charge-offs originated in 2021/2020	9	40
Gross charge-offs originated prior to 2021/2020	58	50
Gross charge-offs originated within the revolving period	26	6
Gross charge-offs originated converted to term loans	106	0
Total gross charge-offs	474	173
Wholesale | Other | Financial institutions
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	245,100	94,000
Loans by origination year
Total retained loans	245,100	94,000
Wholesale | Other | Individuals and individual entities
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	141,100	114,800
Loans by origination year
Total retained loans	141,100	114,800
Wholesale | Other | SPEs
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	7,400	92,500
Loans by origination year
Total retained loans	7,400	92,500
Wholesale | Other | Investment-grade
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	355,547	286,528
Loans by origination year
Term loans originated in 2025/2024	43,073	30,484
Term loans originated in 2024/2023	13,123	17,039
Term loans originated in 2023/2022	7,939	13,272
Term loans originated in 2022/2021	10,838	6,288
Term loans originated in 2021/2020	5,574	8,632
Term loans originated prior to 2021/2020	11,757	7,382
Revolving loans within revolving period	263,150	201,949
Revolving loans converted to term loans	93	1,482
Total retained loans	355,547	286,528
Wholesale | Other | Total noninvestment-grade
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	96,872	74,646
Loans by origination year
Term loans originated in 2025/2024	16,162	11,784
Term loans originated in 2024/2023	6,456	7,248
Term loans originated in 2023/2022	4,425	5,918
Term loans originated in 2022/2021	4,079	3,296
Term loans originated in 2021/2020	2,013	1,366
Term loans originated prior to 2021/2020	2,563	1,886
Revolving loans within revolving period	61,095	42,954
Revolving loans converted to term loans	79	194
Total retained loans	96,872	74,646
Wholesale | Other | Noncriticized
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	93,273	72,743
Loans by origination year
Total retained loans	93,273	72,743
Wholesale | Other | Criticized performing
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	2,833	1,160
Loans by origination year
Total retained loans	2,833	1,160
Wholesale | Other | Criticized nonaccrual
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	766	743
Loans by origination year
Total retained loans	$ 766	$ 743