Investment Securities - Schedule of Contractual Maturities of Debt Securities (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	$ 8,638
Available for sale, under 1 year, fair value	8,550
Available for sale, 1 to 5 years, amortized cost	18,151
Available for sale, 1 to 5 years, fair value	17,480
Available for sale, 6 to 10 years, amortized cost	11,912
Available for sale, 6 to 10 years, fair value	11,781
Available for sale, over 10 years, amortized cost	5,150
Available for sale, over 10 years, fair value	5,030
Available for sale, amortized cost	43,851	$ 41,858
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
Direct obligations
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	1,505
Available for sale, under 1 year, fair value	1,492
Available for sale, 1 to 5 years, amortized cost	5,781
Available for sale, 1 to 5 years, fair value	5,577
Available for sale, 6 to 10 years, amortized cost	548
Available for sale, 6 to 10 years, fair value	558
Available for sale, over 10 years, amortized cost	0
Available for sale, over 10 years, fair value	0
Available for sale, amortized cost	7,834	8,232
Available for sale, fair value	7,627	7,981
Held to maturity, under 1 year, amortized cost	5,771
Held to maturity, under 1 year, fair value	5,681
Held to maturity, 1 to 5 years, amortized cost	5,940
Held to maturity, 1 to 5 years, fair value	5,774
Held to maturity, 6 to 10 years, amortized cost	24
Held to maturity, 6 to 10 years, fair value	23
Held to maturity, over 10 years, amortized cost	12
Held to maturity, over 10 years, fair value	11
Held to maturity, amortized cost	11,747	11,693
Investment securities held-to-maturity	11,489	11,352
Mortgage-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	56
Available for sale, under 1 year, fair value	55
Available for sale, 1 to 5 years, amortized cost	633
Available for sale, 1 to 5 years, fair value	627
Available for sale, 6 to 10 years, amortized cost	5,987
Available for sale, 6 to 10 years, fair value	5,914
Available for sale, over 10 years, amortized cost	2,669
Available for sale, over 10 years, fair value	2,584
Available for sale, amortized cost	9,345	8,767
Available for sale, fair value	9,180	8,509
Held to maturity, under 1 year, amortized cost	144
Held to maturity, under 1 year, fair value	133
Held to maturity, 1 to 5 years, amortized cost	583
Held to maturity, 1 to 5 years, fair value	550
Held to maturity, 6 to 10 years, amortized cost	4,579
Held to maturity, 6 to 10 years, fair value	3,883
Held to maturity, over 10 years, amortized cost	36,956
Held to maturity, over 10 years, fair value	32,413
Held to maturity, amortized cost	42,262	42,307
Investment securities held-to-maturity	36,979	36,280
Total U.S. Treasury and federal agencies
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	1,561
Available for sale, under 1 year, fair value	1,547
Available for sale, 1 to 5 years, amortized cost	6,414
Available for sale, 1 to 5 years, fair value	6,204
Available for sale, 6 to 10 years, amortized cost	6,535
Available for sale, 6 to 10 years, fair value	6,472
Available for sale, over 10 years, amortized cost	2,669
Available for sale, over 10 years, fair value	2,584
Available for sale, amortized cost	17,179	16,999
Available for sale, fair value	16,807	16,490
Held to maturity, under 1 year, amortized cost	5,915
Held to maturity, under 1 year, fair value	5,814
Held to maturity, 1 to 5 years, amortized cost	6,523
Held to maturity, 1 to 5 years, fair value	6,324
Held to maturity, 6 to 10 years, amortized cost	4,603
Held to maturity, 6 to 10 years, fair value	3,906
Held to maturity, over 10 years, amortized cost	36,968
Held to maturity, over 10 years, fair value	32,424
Held to maturity, amortized cost	54,009	54,000
Investment securities held-to-maturity	48,468	47,632
Mortgage-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	120
Available for sale, under 1 year, fair value	120
Available for sale, 1 to 5 years, amortized cost	321
Available for sale, 1 to 5 years, fair value	320
Available for sale, 6 to 10 years, amortized cost	0
Available for sale, 6 to 10 years, fair value	0
Available for sale, over 10 years, amortized cost	1,135
Available for sale, over 10 years, fair value	1,123
Available for sale, amortized cost	1,576	1,642
Available for sale, fair value	1,563	1,623
Asset-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	340
Available for sale, under 1 year, fair value	335
Available for sale, 1 to 5 years, amortized cost	545
Available for sale, 1 to 5 years, fair value	537
Available for sale, 6 to 10 years, amortized cost	487
Available for sale, 6 to 10 years, fair value	481
Available for sale, over 10 years, amortized cost	330
Available for sale, over 10 years, fair value	325
Available for sale, amortized cost	1,702	1,696
Available for sale, fair value	1,678	1,669
Non-U.S. sovereign, supranational and non-U.S. agency
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	5,815
Available for sale, under 1 year, fair value	5,759
Available for sale, 1 to 5 years, amortized cost	7,371
Available for sale, 1 to 5 years, fair value	7,100
Available for sale, 6 to 10 years, amortized cost	3,016
Available for sale, 6 to 10 years, fair value	2,991
Available for sale, over 10 years, amortized cost	0
Available for sale, over 10 years, fair value	0
Available for sale, amortized cost	16,202	14,512
Available for sale, fair value	15,850	14,089
Held to maturity, under 1 year, amortized cost	2,119
Held to maturity, under 1 year, fair value	2,083
Held to maturity, 1 to 5 years, amortized cost	4,398
Held to maturity, 1 to 5 years, fair value	4,221
Held to maturity, 6 to 10 years, amortized cost	711
Held to maturity, 6 to 10 years, fair value	666
Held to maturity, over 10 years, amortized cost	0
Held to maturity, over 10 years, fair value	0
Held to maturity, amortized cost	7,228	6,603
Investment securities held-to-maturity	6,970	6,299
Other
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	290
Available for sale, under 1 year, fair value	285
Available for sale, 1 to 5 years, amortized cost	1,949
Available for sale, 1 to 5 years, fair value	1,834
Available for sale, 6 to 10 years, amortized cost	206
Available for sale, 6 to 10 years, fair value	188
Available for sale, over 10 years, amortized cost	9
Available for sale, over 10 years, fair value	8
Available for sale, amortized cost	2,454	2,255
Available for sale, fair value	2,315	2,091
Total non-U.S. debt securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	6,565
Available for sale, under 1 year, fair value	6,499
Available for sale, 1 to 5 years, amortized cost	10,186
Available for sale, 1 to 5 years, fair value	9,791
Available for sale, 6 to 10 years, amortized cost	3,709
Available for sale, 6 to 10 years, fair value	3,660
Available for sale, over 10 years, amortized cost	1,474
Available for sale, over 10 years, fair value	1,456
Available for sale, amortized cost	21,934	20,105
Available for sale, fair value	21,406	19,472
Held to maturity, under 1 year, amortized cost	2,119
Held to maturity, under 1 year, fair value	2,083
Held to maturity, 1 to 5 years, amortized cost	4,398
Held to maturity, 1 to 5 years, fair value	4,221
Held to maturity, 6 to 10 years, amortized cost	711
Held to maturity, 6 to 10 years, fair value	666
Held to maturity, over 10 years, amortized cost	0
Held to maturity, over 10 years, fair value	0
Held to maturity, amortized cost	7,228	6,603
Investment securities held-to-maturity	6,970	6,299
Student loans
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	37
Available for sale, under 1 year, fair value	37
Available for sale, 1 to 5 years, amortized cost	0
Available for sale, 1 to 5 years, fair value	0
Available for sale, 6 to 10 years, amortized cost	0
Available for sale, 6 to 10 years, fair value	0
Available for sale, over 10 years, amortized cost	73
Available for sale, over 10 years, fair value	73
Available for sale, amortized cost	110	116
Available for sale, fair value	110	115
Held to maturity, under 1 year, amortized cost	266
Held to maturity, under 1 year, fair value	258
Held to maturity, 1 to 5 years, amortized cost	7
Held to maturity, 1 to 5 years, fair value	7
Held to maturity, 6 to 10 years, amortized cost	892
Held to maturity, 6 to 10 years, fair value	873
Held to maturity, over 10 years, amortized cost	2,575
Held to maturity, over 10 years, fair value	2,495
Held to maturity, amortized cost	3,740	3,955
Investment securities held-to-maturity	3,633	3,822
Collateralized loan obligations
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	118
Available for sale, under 1 year, fair value	117
Available for sale, 1 to 5 years, amortized cost	383
Available for sale, 1 to 5 years, fair value	377
Available for sale, 6 to 10 years, amortized cost	1,292
Available for sale, 6 to 10 years, fair value	1,274
Available for sale, over 10 years, amortized cost	644
Available for sale, over 10 years, fair value	638
Available for sale, amortized cost	2,437	2,394
Available for sale, fair value	2,406	2,355
Non-agency CMBS and RMBS
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	0
Available for sale, under 1 year, fair value	0
Available for sale, 1 to 5 years, amortized cost	20
Available for sale, 1 to 5 years, fair value	20
Available for sale, 6 to 10 years, amortized cost	0
Available for sale, 6 to 10 years, fair value	0
Available for sale, over 10 years, amortized cost	246
Available for sale, over 10 years, fair value	240
Available for sale, amortized cost	266	237
Available for sale, fair value	260	231
Held to maturity, under 1 year, amortized cost	43
Held to maturity, under 1 year, fair value	49
Held to maturity, 1 to 5 years, amortized cost	0
Held to maturity, 1 to 5 years, fair value	0
Held to maturity, 6 to 10 years, amortized cost	0
Held to maturity, 6 to 10 years, fair value	0
Held to maturity, over 10 years, amortized cost	7
Held to maturity, over 10 years, fair value	19
Held to maturity, amortized cost	50	142
Investment securities held-to-maturity	68	160
Other
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	0
Available for sale, under 1 year, fair value	0
Available for sale, 1 to 5 years, amortized cost	90
Available for sale, 1 to 5 years, fair value	90
Available for sale, 6 to 10 years, amortized cost	0
Available for sale, 6 to 10 years, fair value	0
Available for sale, over 10 years, amortized cost	0
Available for sale, over 10 years, fair value	0
Available for sale, amortized cost	90	90
Available for sale, fair value	90	88
Total asset-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	155
Available for sale, under 1 year, fair value	154
Available for sale, 1 to 5 years, amortized cost	493
Available for sale, 1 to 5 years, fair value	487
Available for sale, 6 to 10 years, amortized cost	1,292
Available for sale, 6 to 10 years, fair value	1,274
Available for sale, over 10 years, amortized cost	963
Available for sale, over 10 years, fair value	951
Available for sale, amortized cost	2,903	2,837
Available for sale, fair value	2,866	2,789
Held to maturity, under 1 year, amortized cost	309
Held to maturity, under 1 year, fair value	307
Held to maturity, 1 to 5 years, amortized cost	7
Held to maturity, 1 to 5 years, fair value	7
Held to maturity, 6 to 10 years, amortized cost	892
Held to maturity, 6 to 10 years, fair value	873
Held to maturity, over 10 years, amortized cost	2,582
Held to maturity, over 10 years, fair value	2,514
Held to maturity, amortized cost	3,790	4,097
Investment securities held-to-maturity	3,701	3,982
State and political subdivisions
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	126
Available for sale, under 1 year, fair value	125
Available for sale, 1 to 5 years, amortized cost	269
Available for sale, 1 to 5 years, fair value	264
Available for sale, 6 to 10 years, amortized cost	347
Available for sale, 6 to 10 years, fair value	349
Available for sale, over 10 years, amortized cost	44
Available for sale, over 10 years, fair value	39
Available for sale, amortized cost	786	839
Available for sale, fair value	777	823
Other U.S. debt securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	231
Available for sale, under 1 year, fair value	225
Available for sale, 1 to 5 years, amortized cost	789
Available for sale, 1 to 5 years, fair value	734
Available for sale, 6 to 10 years, amortized cost	29
Available for sale, 6 to 10 years, fair value	26
Available for sale, over 10 years, amortized cost	0
Available for sale, over 10 years, fair value	0
Available for sale, amortized cost	1,049	1,078
Available for sale, fair value	985	$ 1,005
Total
Contractual Maturities Of Debt Investment Securities [Line Items]
Held to maturity, under 1 year, amortized cost	8,343
Held to maturity, under 1 year, fair value	8,204
Held to maturity, 1 to 5 years, amortized cost	10,928
Held to maturity, 1 to 5 years, fair value	10,552
Held to maturity, 6 to 10 years, amortized cost	6,206
Held to maturity, 6 to 10 years, fair value	5,445
Held to maturity, over 10 years, amortized cost	39,550
Held to maturity, over 10 years, fair value	34,938
Held to maturity, amortized cost	65,027
Investment securities held-to-maturity	$ 59,139