Investment Securities - Schedule of Marketable Securities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	$ 41,858	$ 73,440
Available for sale, gross unrealized gains	14	404
Available for sale, gross unrealized losses	1,293	445
Available-for-sale investment securities:	40,579	73,399
Held to maturity, amortized cost	64,700	42,430
Investment securities held-to-maturity	57,913	42,271
Debt securities, AFS, allowance	2	2	$ 0
US Treasury and federal agencies, direct obligations
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	8,232	18,111
Available for sale, gross unrealized gains	10	24
Available for sale, gross unrealized losses	261	196
Available-for-sale investment securities:	7,981	17,939
Held to maturity, amortized cost	11,693	2,170
Held to maturity, gross unrealized gains	0	10
Held to maturity, gross unrealized losses	341	0
Investment securities held-to-maturity	11,352	2,180
US Treasury and federal agencies, mortgage-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	8,767	18,154
Available for sale, gross unrealized gains	2	148
Available for sale, gross unrealized losses	260	94
Available-for-sale investment securities:	8,509	18,208
Held to maturity, amortized cost	42,307	33,481
Held to maturity, gross unrealized gains	3	362
Held to maturity, gross unrealized losses	6,030	578
Investment securities held-to-maturity	36,280	33,265
Total U.S. Treasury and federal agencies
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	16,999	36,265
Available for sale, gross unrealized gains	12	172
Available for sale, gross unrealized losses	521	290
Available-for-sale investment securities:	16,490	36,147
Held to maturity, amortized cost	54,000	35,651
Held to maturity, gross unrealized gains	3	372
Held to maturity, gross unrealized losses	6,371	578
Investment securities held-to-maturity	47,632	35,445
Non-U.S. debt securities, mortgage-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	1,642	1,986
Available for sale, gross unrealized gains	0	12
Available for sale, gross unrealized losses	19	3
Available-for-sale investment securities:	1,623	1,995
Non-U.S. debt securities, asset-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	1,696	2,087
Available for sale, gross unrealized gains	0	2
Available for sale, gross unrealized losses	27	2
Available-for-sale investment securities:	1,669	2,087
Non-U.S. sovereign, supranational and non-U.S. agency
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	14,512	23,533
Available for sale, gross unrealized gains	1	114
Available for sale, gross unrealized losses	424	100
Available-for-sale investment securities:	14,089	23,547
Held to maturity, amortized cost	6,603	1,564
Held to maturity, gross unrealized gains	0	0
Held to maturity, gross unrealized losses	304	9
Investment securities held-to-maturity	6,299	1,555
Non-U.S. debt securities, other
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	2,255	3,113
Available for sale, gross unrealized gains	0	17
Available for sale, gross unrealized losses	164	32
Available-for-sale investment securities:	2,091	3,098
Total non-U.S. debt securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	20,105	30,719
Available for sale, gross unrealized gains	1	145
Available for sale, gross unrealized losses	634	137
Available-for-sale investment securities:	19,472	30,727
Held to maturity, amortized cost	6,603	1,564
Held to maturity, gross unrealized gains	0	0
Held to maturity, gross unrealized losses	304	9
Investment securities held-to-maturity	6,299	1,555
Asset-backed securities, student loans
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	116	209
Available for sale, gross unrealized gains	0	2
Available for sale, gross unrealized losses	1	0
Available-for-sale investment securities:	115	211
Held to maturity, amortized cost	3,955	4,908
Held to maturity, gross unrealized gains	1	48
Held to maturity, gross unrealized losses	134	14
Investment securities held-to-maturity	3,822	4,942
Asset-backed securities, collateralized loan obligations
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	2,394	2,155
Available for sale, gross unrealized gains	0	2
Available for sale, gross unrealized losses	39	2
Available-for-sale investment securities:	2,355	2,155
Asset-backed securities, non-agency CMBS and RMBS
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	237	52
Available for sale, gross unrealized gains	0	0
Available for sale, gross unrealized losses	6	0
Available-for-sale investment securities:	231	52
Held to maturity, amortized cost	142	307
Held to maturity, gross unrealized gains	18	22
Held to maturity, gross unrealized losses	0	0
Investment securities held-to-maturity	160	329
Asset-backed securities, other
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	90	90
Available for sale, gross unrealized gains	0	1
Available for sale, gross unrealized losses	2	0
Available-for-sale investment securities:	88	91
Total asset-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	2,837	2,506
Available for sale, gross unrealized gains	0	5
Available for sale, gross unrealized losses	48	2
Available-for-sale investment securities:	2,789	2,509
Held to maturity, amortized cost	4,097	5,215
Held to maturity, gross unrealized gains	19	70
Held to maturity, gross unrealized losses	134	14
Investment securities held-to-maturity	3,982	5,271
State and political subdivisions
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	839	1,216
Available for sale, gross unrealized gains	1	59
Available for sale, gross unrealized losses	17	3
Available-for-sale investment securities:	823	1,272
Other U.S. debt securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	1,078	2,734
Available for sale, gross unrealized gains	0	23
Available for sale, gross unrealized losses	73	13
Available-for-sale investment securities:	1,005	2,744
Including money market mutual fund liquidity facility
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Held to maturity, amortized cost	64,700	42,430
Held to maturity, gross unrealized gains	22	442
Held to maturity, gross unrealized losses	6,809	601
Investment securities held-to-maturity	57,913	42,271
Non-US collateralized loan obligations
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	860	830
Non-U.S. debt securities, corporate bonds
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	$ 1,140	1,530
Federal family education loan program
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Federal government credit support guarantee, percentage minimum	97.00%
US corporate bonds
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	$ 1,010	2,440
Non-agency CMBS
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Debt securities, held-to-maturity, amortized cost, before allowance for credit loss	133	292
Non-agency RMBS
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Debt securities, held-to-maturity, amortized cost, before allowance for credit loss	$ 9	$ 14