Loans - Wholesale Loan Portfolio, Internal Risk Ratings (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 1,089,598	$ 1,010,206	$ 960,506
Wholesale
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 603,670	$ 560,354	$ 514,947
% of investment-grade to total retained loans	70.47%	73.17%
% of total criticized to total retained loans	2.60%	2.39%
% of criticized nonaccrual to total retained loans	0.33%	0.37%
Wholesale | Paycheck Protection Program (PPP) | 90 or more days past due
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 0	$ 127
Wholesale | Investment-grade
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	425,412	410,011
Wholesale | Investment-grade | Paycheck Protection Program (PPP)
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	140	1,300
Wholesale | Total noninvestment- grade
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	178,258	150,343
Wholesale | Noncriticized
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	162,553	136,974
Wholesale | Criticized performing
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	13,742	11,315
Wholesale | Criticized nonaccrual
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	1,963	2,054
Wholesale | Secured by real estate
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 126,732	$ 118,835
% of investment-grade to total retained loans	78.55%	77.73%
% of total criticized to total retained loans	3.08%	3.34%
% of criticized nonaccrual to total retained loans	0.19%	0.27%
Term loans originated in 2022/2021	$ 30,206	$ 28,710
Term loans originated in 2021/2020	28,009	19,856
Term loans originated in 2020/2019	17,805	21,829
Term loans originated in 2019/2018	18,164	11,909
Term loans originated in 2018/2017	7,672	10,159
Term loans originated prior to 2018/2017	22,948	24,679
Revolving loans within revolving period	1,926	1,684
Revolving loans converted to term loans	2	9
Wholesale | Secured by real estate | Investment-grade
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	99,552	92,369
Term loans originated in 2022/2021	24,134	23,346
Term loans originated in 2021/2020	22,407	16,030
Term loans originated in 2020/2019	14,773	17,265
Term loans originated in 2019/2018	14,666	8,103
Term loans originated in 2018/2017	5,277	7,325
Term loans originated prior to 2018/2017	17,289	19,066
Revolving loans within revolving period	1,006	1,226
Revolving loans converted to term loans	0	8
Wholesale | Secured by real estate | Total noninvestment- grade
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	27,180	26,466
Term loans originated in 2022/2021	6,072	5,364
Term loans originated in 2021/2020	5,602	3,826
Term loans originated in 2020/2019	3,032	4,564
Term loans originated in 2019/2018	3,498	3,806
Term loans originated in 2018/2017	2,395	2,834
Term loans originated prior to 2018/2017	5,659	5,613
Revolving loans within revolving period	920	458
Revolving loans converted to term loans	2	1
Wholesale | Secured by real estate | Noncriticized
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	23,272	22,495
Wholesale | Secured by real estate | Criticized performing
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	3,662	3,645
Wholesale | Secured by real estate | Criticized nonaccrual
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 246	$ 326
% of criticized nonaccrual to total retained loans	0.19%	0.27%
Wholesale | Commercial and industrial
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 167,660	$ 145,691
% of investment-grade to total retained loans	45.49%	52.02%
% of total criticized to total retained loans	5.96%	5.40%
% of criticized nonaccrual to total retained loans	0.61%	0.67%
Term loans originated in 2022/2021	$ 45,160	$ 40,656
Term loans originated in 2021/2020	20,782	13,380
Term loans originated in 2020/2019	6,504	8,168
Term loans originated in 2019/2018	4,501	3,446
Term loans originated in 2018/2017	1,273	2,038
Term loans originated prior to 2018/2017	2,003	1,249
Revolving loans within revolving period	87,354	76,679
Revolving loans converted to term loans	83	75
Wholesale | Commercial and industrial | Investment-grade
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	76,275	75,783
Term loans originated in 2022/2021	21,072	21,342
Term loans originated in 2021/2020	8,338	6,268
Term loans originated in 2020/2019	3,045	3,609
Term loans originated in 2019/2018	1,995	1,269
Term loans originated in 2018/2017	748	1,108
Term loans originated prior to 2018/2017	989	819
Revolving loans within revolving period	40,087	41,367
Revolving loans converted to term loans	1	1
Wholesale | Commercial and industrial | Investment-grade | Paycheck Protection Program (PPP)
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	139	1,100
Term loans originated in 2022/2021		698
Term loans originated in 2021/2020	58	396
Term loans originated in 2020/2019	81
Wholesale | Commercial and industrial | Total noninvestment- grade
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	91,385	69,908
Term loans originated in 2022/2021	24,088	19,314
Term loans originated in 2021/2020	12,444	7,112
Term loans originated in 2020/2019	3,459	4,559
Term loans originated in 2019/2018	2,506	2,177
Term loans originated in 2018/2017	525	930
Term loans originated prior to 2018/2017	1,014	430
Revolving loans within revolving period	47,267	35,312
Revolving loans converted to term loans	82	74
Wholesale | Commercial and industrial | Noncriticized
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	81,393	62,039
Wholesale | Commercial and industrial | Criticized performing
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	8,974	6,900
Wholesale | Commercial and industrial | Criticized nonaccrual
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	1,018	969
Wholesale | Other
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 309,278	$ 295,828
% of investment-grade to total retained loans	80.70%	81.76%
% of total criticized to total retained loans	0.58%	0.52%
% of criticized nonaccrual to total retained loans	0.23%	0.26%
Term loans originated in 2022/2021	$ 48,950	$ 43,687
Term loans originated in 2021/2020	22,960	20,228
Term loans originated in 2020/2019	14,836	7,580
Term loans originated in 2019/2018	5,228	3,820
Term loans originated in 2018/2017	2,610	4,086
Term loans originated prior to 2018/2017	7,726	8,118
Revolving loans within revolving period	203,289	207,703
Revolving loans converted to term loans	3,679	606
Wholesale | Other | Investment-grade
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	249,585	241,859
Term loans originated in 2022/2021	32,121	26,782
Term loans originated in 2021/2020	15,864	17,829
Term loans originated in 2020/2019	13,015	6,125
Term loans originated in 2019/2018	4,529	2,885
Term loans originated in 2018/2017	2,159	3,868
Term loans originated prior to 2018/2017	7,251	7,651
Revolving loans within revolving period	171,049	176,118
Revolving loans converted to term loans	3,597	601
Wholesale | Other | Total noninvestment- grade
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	59,693	53,969
Term loans originated in 2022/2021	16,829	16,905
Term loans originated in 2021/2020	7,096	2,399
Term loans originated in 2020/2019	1,821	1,455
Term loans originated in 2019/2018	699	935
Term loans originated in 2018/2017	451	218
Term loans originated prior to 2018/2017	475	467
Revolving loans within revolving period	32,240	31,585
Revolving loans converted to term loans	82	5
Wholesale | Other | Noncriticized
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	57,888	52,440
Wholesale | Other | Criticized performing
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	1,106	770
Wholesale | Other | Criticized nonaccrual
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 699	$ 759