Investment Securities - Schedule of Marketable Securities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	$ 43,851	$ 41,858
Available for sale, gross unrealized gains	27	14
Available for sale, gross unrealized losses	1,037	1,293
Available-for-sale, fair value	42,841	40,579
Held to maturity, amortized cost	65,027	64,700
Investment securities held-to-maturity	59,139	57,913
Allowance for credit losses on available-for-sale securities	2	2
Direct obligations
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	7,834	8,232
Available for sale, gross unrealized gains	11	10
Available for sale, gross unrealized losses	218	261
Available-for-sale, fair value	7,627	7,981
Held to maturity, amortized cost	11,747	11,693
Held to maturity, gross unrealized gains	0	0
Held to maturity, gross unrealized losses	258	341
Investment securities held-to-maturity	11,489	11,352
Mortgage-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	9,345	8,767
Available for sale, gross unrealized gains	4	2
Available for sale, gross unrealized losses	169	260
Available-for-sale, fair value	9,180	8,509
Held to maturity, amortized cost	42,262	42,307
Held to maturity, gross unrealized gains	11	3
Held to maturity, gross unrealized losses	5,294	6,030
Investment securities held-to-maturity	36,979	36,280
Total U.S. Treasury and federal agencies
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	17,179	16,999
Available for sale, gross unrealized gains	15	12
Available for sale, gross unrealized losses	387	521
Available-for-sale, fair value	16,807	16,490
Held to maturity, amortized cost	54,009	54,000
Held to maturity, gross unrealized gains	11	3
Held to maturity, gross unrealized losses	5,552	6,371
Investment securities held-to-maturity	48,468	47,632
Mortgage-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	1,576	1,642
Available for sale, gross unrealized gains	1	0
Available for sale, gross unrealized losses	14	19
Available-for-sale, fair value	1,563	1,623
Asset-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	1,702	1,696
Available for sale, gross unrealized gains	0	0
Available for sale, gross unrealized losses	24	27
Available-for-sale, fair value	1,678	1,669
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	16,202	14,512
Available for sale, gross unrealized gains	6	1
Available for sale, gross unrealized losses	358	424
Available-for-sale, fair value	15,850	14,089
Held to maturity, amortized cost	7,228	6,603
Held to maturity, gross unrealized gains	1	0
Held to maturity, gross unrealized losses	259	304
Investment securities held-to-maturity	6,970	6,299
Other
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	2,454	2,255
Available for sale, gross unrealized gains	2	0
Available for sale, gross unrealized losses	141	164
Available-for-sale, fair value	2,315	2,091
Total non-U.S. debt securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	21,934	20,105
Available for sale, gross unrealized gains	9	1
Available for sale, gross unrealized losses	537	634
Available-for-sale, fair value	21,406	19,472
Held to maturity, amortized cost	7,228	6,603
Held to maturity, gross unrealized gains	1	0
Held to maturity, gross unrealized losses	259	304
Investment securities held-to-maturity	6,970	6,299
Student loans
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	110	116
Available for sale, gross unrealized gains	0	0
Available for sale, gross unrealized losses	0	1
Available-for-sale, fair value	110	115
Held to maturity, amortized cost	3,740	3,955
Held to maturity, gross unrealized gains	1	1
Held to maturity, gross unrealized losses	108	134
Investment securities held-to-maturity	3,633	3,822
Collateralized loan obligations
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	2,437	2,394
Available for sale, gross unrealized gains	0	0
Available for sale, gross unrealized losses	31	39
Available-for-sale, fair value	2,406	2,355
Non-agency CMBS and RMBS
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	266	237
Available for sale, gross unrealized gains	0	0
Available for sale, gross unrealized losses	6	6
Available-for-sale, fair value	260	231
Held to maturity, amortized cost	50	142
Held to maturity, gross unrealized gains	18	18
Held to maturity, gross unrealized losses	0	0
Investment securities held-to-maturity	68	160
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	0
Available for sale, gross unrealized losses	0	2
Available-for-sale, fair value	90	88
Total asset-backed securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	2,903	2,837
Available for sale, gross unrealized gains	0	0
Available for sale, gross unrealized losses	37	48
Available-for-sale, fair value	2,866	2,789
Held to maturity, amortized cost	3,790	4,097
Held to maturity, gross unrealized gains	19	19
Held to maturity, gross unrealized losses	108	134
Investment securities held-to-maturity	3,701	3,982
State and political subdivisions
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	786	839
Available for sale, gross unrealized gains	3	1
Available for sale, gross unrealized losses	12	17
Available-for-sale, fair value	777	823
Other U.S. debt securities
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	1,049	1,078
Available for sale, gross unrealized gains	0	0
Available for sale, gross unrealized losses	64	73
Available-for-sale, fair value	985	1,005
Including MMLF
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Held to maturity, amortized cost	65,027	64,700
Held to maturity, gross unrealized gains	31	22
Held to maturity, gross unrealized losses	5,919	6,809
Investment securities held-to-maturity	59,139	57,913
Non-US collateralized loan obligations
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	900	860
Non-U.S. debt securities, corporate bonds
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	1,390	1,140
US debt securities, corporate bonds
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	990	1,010
Non-agency CMBS
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Held to maturity, amortized cost	42	133
Non-agency RMBS
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Held to maturity, amortized cost	$ 8	9
Federal family education loan program
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Federal government credit support guarantee, percentage minimum	97.00%
Agency CMBS
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	$ 6,530	6,780
Held to maturity, amortized cost	5,290	4,990
Agency MBS
Available-For-Sale and Held-To-Maturity-Securities [Line Items]
Available for sale, amortized cost	$ 2,650	$ 1,730