Investment Securities - Schedule of Contractual Maturities of Debt Securities (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	$ 8,163
Available for sale, under 1 year, fair value	8,089
Available for sale, 1 to 5 years, amortized cost	19,361
Available for sale, 1 to 5 years, fair value	18,581
Available for sale, 6 to 10 years, amortized cost	11,240
Available for sale, 6 to 10 years, fair value	11,058
Available for sale, over 10 years, amortized cost	5,449
Available for sale, over 10 years, fair value	5,318
Available for sale, amortized cost	44,213	$ 41,858
Available for sale, fair value	43,046	40,579
Held to maturity, amortized cost	63,510	64,700
Investment securities held-to-maturity	56,863	57,913
Direct obligations
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	789
Available for sale, under 1 year, fair value	787
Available for sale, 1 to 5 years, amortized cost	5,850
Available for sale, 1 to 5 years, fair value	5,667
Available for sale, 6 to 10 years, amortized cost	633
Available for sale, 6 to 10 years, fair value	642
Available for sale, over 10 years, amortized cost	0
Available for sale, over 10 years, fair value	0
Available for sale, amortized cost	7,272	8,232
Available for sale, fair value	7,096	7,981
Held to maturity, under 1 year, amortized cost	5,797
Held to maturity, under 1 year, fair value	5,718
Held to maturity, 1 to 5 years, amortized cost	5,969
Held to maturity, 1 to 5 years, fair value	5,722
Held to maturity, 6 to 10 years, amortized cost	24
Held to maturity, 6 to 10 years, fair value	22
Held to maturity, over 10 years, amortized cost	12
Held to maturity, over 10 years, fair value	12
Held to maturity, amortized cost	11,802	11,693
Investment securities held-to-maturity	11,474	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	804
Available for sale, 1 to 5 years, fair value	793
Available for sale, 6 to 10 years, amortized cost	5,287
Available for sale, 6 to 10 years, fair value	5,180
Available for sale, over 10 years, amortized cost	3,181
Available for sale, over 10 years, fair value	3,075
Available for sale, amortized cost	9,328	8,767
Available for sale, fair value	9,103	8,509
Held to maturity, under 1 year, amortized cost	136
Held to maturity, under 1 year, fair value	121
Held to maturity, 1 to 5 years, amortized cost	570
Held to maturity, 1 to 5 years, fair value	530
Held to maturity, 6 to 10 years, amortized cost	4,611
Held to maturity, 6 to 10 years, fair value	3,853
Held to maturity, over 10 years, amortized cost	35,997
Held to maturity, over 10 years, fair value	30,848
Held to maturity, amortized cost	41,314	42,307
Investment securities held-to-maturity	35,352	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	845
Available for sale, under 1 year, fair value	842
Available for sale, 1 to 5 years, amortized cost	6,654
Available for sale, 1 to 5 years, fair value	6,460
Available for sale, 6 to 10 years, amortized cost	5,920
Available for sale, 6 to 10 years, fair value	5,822
Available for sale, over 10 years, amortized cost	3,181
Available for sale, over 10 years, fair value	3,075
Available for sale, amortized cost	16,600	16,999
Available for sale, fair value	16,199	16,490
Held to maturity, under 1 year, amortized cost	5,933
Held to maturity, under 1 year, fair value	5,839
Held to maturity, 1 to 5 years, amortized cost	6,539
Held to maturity, 1 to 5 years, fair value	6,252
Held to maturity, 6 to 10 years, amortized cost	4,635
Held to maturity, 6 to 10 years, fair value	3,875
Held to maturity, over 10 years, amortized cost	36,009
Held to maturity, over 10 years, fair value	30,860
Held to maturity, amortized cost	53,116	54,000
Investment securities held-to-maturity	46,826	47,632
Mortgage-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	156
Available for sale, under 1 year, fair value	156
Available for sale, 1 to 5 years, amortized cost	261
Available for sale, 1 to 5 years, fair value	261
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	1,118
Available for sale, over 10 years, fair value	1,107
Available for sale, amortized cost	1,535	1,642
Available for sale, fair value	1,524	1,623
Asset-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	328
Available for sale, under 1 year, fair value	323
Available for sale, 1 to 5 years, amortized cost	491
Available for sale, 1 to 5 years, fair value	485
Available for sale, 6 to 10 years, amortized cost	479
Available for sale, 6 to 10 years, fair value	473
Available for sale, over 10 years, amortized cost	299
Available for sale, over 10 years, fair value	296
Available for sale, amortized cost	1,597	1,696
Available for sale, fair value	1,577	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	6,024
Available for sale, under 1 year, fair value	5,971
Available for sale, 1 to 5 years, amortized cost	8,554
Available for sale, 1 to 5 years, fair value	8,172
Available for sale, 6 to 10 years, amortized cost	2,813
Available for sale, 6 to 10 years, fair value	2,778
Available for sale, over 10 years, amortized cost	0
Available for sale, over 10 years, fair value	0
Available for sale, amortized cost	17,391	14,512
Available for sale, fair value	16,921	14,089
Held to maturity, under 1 year, amortized cost	2,495
Held to maturity, under 1 year, fair value	2,441
Held to maturity, 1 to 5 years, amortized cost	3,663
Held to maturity, 1 to 5 years, fair value	3,481
Held to maturity, 6 to 10 years, amortized cost	644
Held to maturity, 6 to 10 years, fair value	600
Held to maturity, over 10 years, amortized cost	0
Held to maturity, over 10 years, fair value	0
Held to maturity, amortized cost	6,802	6,603
Investment securities held-to-maturity	6,522	6,299
Other
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	274
Available for sale, under 1 year, fair value	269
Available for sale, 1 to 5 years, amortized cost	1,931
Available for sale, 1 to 5 years, fair value	1,798
Available for sale, 6 to 10 years, amortized cost	205
Available for sale, 6 to 10 years, fair value	183
Available for sale, over 10 years, amortized cost	10
Available for sale, over 10 years, fair value	7
Available for sale, amortized cost	2,420	2,255
Available for sale, fair value	2,257	2,091
Total non-U.S. debt securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	6,782
Available for sale, under 1 year, fair value	6,719
Available for sale, 1 to 5 years, amortized cost	11,237
Available for sale, 1 to 5 years, fair value	10,716
Available for sale, 6 to 10 years, amortized cost	3,497
Available for sale, 6 to 10 years, fair value	3,434
Available for sale, over 10 years, amortized cost	1,427
Available for sale, over 10 years, fair value	1,410
Available for sale, amortized cost	22,943	20,105
Available for sale, fair value	22,279	19,472
Held to maturity, under 1 year, amortized cost	2,495
Held to maturity, under 1 year, fair value	2,441
Held to maturity, 1 to 5 years, amortized cost	3,663
Held to maturity, 1 to 5 years, fair value	3,481
Held to maturity, 6 to 10 years, amortized cost	644
Held to maturity, 6 to 10 years, fair value	600
Held to maturity, over 10 years, amortized cost	0
Held to maturity, over 10 years, fair value	0
Held to maturity, amortized cost	6,802	6,603
Investment securities held-to-maturity	6,522	6,299
Student loans
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	35
Available for sale, under 1 year, fair value	35
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	71
Available for sale, over 10 years, fair value	70
Available for sale, amortized cost	106	116
Available for sale, fair value	105	115
Held to maturity, under 1 year, amortized cost	251
Held to maturity, under 1 year, fair value	243
Held to maturity, 1 to 5 years, amortized cost	37
Held to maturity, 1 to 5 years, fair value	36
Held to maturity, 6 to 10 years, amortized cost	851
Held to maturity, 6 to 10 years, fair value	834
Held to maturity, over 10 years, amortized cost	2,445
Held to maturity, over 10 years, fair value	2,376
Held to maturity, amortized cost	3,584	3,955
Investment securities held-to-maturity	3,489	3,822
Collateralized loan obligations
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	121
Available for sale, under 1 year, fair value	120
Available for sale, 1 to 5 years, amortized cost	358
Available for sale, 1 to 5 years, fair value	353
Available for sale, 6 to 10 years, amortized cost	1,458
Available for sale, 6 to 10 years, fair value	1,442
Available for sale, over 10 years, amortized cost	515
Available for sale, over 10 years, fair value	513
Available for sale, amortized cost	2,452	2,394
Available for sale, fair value	2,428	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	255
Available for sale, over 10 years, fair value	250
Available for sale, amortized cost	275	237
Available for sale, fair value	270	231
Held to maturity, under 1 year, amortized cost	2
Held to maturity, under 1 year, fair value	8
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	6
Held to maturity, over 10 years, fair value	18
Held to maturity, amortized cost	8	142
Investment securities held-to-maturity	26	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	156
Available for sale, under 1 year, fair value	155
Available for sale, 1 to 5 years, amortized cost	468
Available for sale, 1 to 5 years, fair value	463
Available for sale, 6 to 10 years, amortized cost	1,458
Available for sale, 6 to 10 years, fair value	1,442
Available for sale, over 10 years, amortized cost	841
Available for sale, over 10 years, fair value	833
Available for sale, amortized cost	2,923	2,837
Available for sale, fair value	2,893	2,789
Held to maturity, under 1 year, amortized cost	253
Held to maturity, under 1 year, fair value	251
Held to maturity, 1 to 5 years, amortized cost	37
Held to maturity, 1 to 5 years, fair value	36
Held to maturity, 6 to 10 years, amortized cost	851
Held to maturity, 6 to 10 years, fair value	834
Held to maturity, over 10 years, amortized cost	2,451
Held to maturity, over 10 years, fair value	2,394
Held to maturity, amortized cost	3,592	4,097
Investment securities held-to-maturity	3,515	3,982
State and political subdivisions
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	125
Available for sale, under 1 year, fair value	124
Available for sale, 1 to 5 years, amortized cost	260
Available for sale, 1 to 5 years, fair value	253
Available for sale, 6 to 10 years, amortized cost	337
Available for sale, 6 to 10 years, fair value	334
Available for sale, over 10 years, amortized cost	0
Available for sale, over 10 years, fair value	0
Available for sale, amortized cost	722	839
Available for sale, fair value	711	823
Other U.S. debt securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	255
Available for sale, under 1 year, fair value	249
Available for sale, 1 to 5 years, amortized cost	742
Available for sale, 1 to 5 years, fair value	689
Available for sale, 6 to 10 years, amortized cost	28
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	1,025	1,078
Available for sale, fair value	964	$ 1,005
Total
Contractual Maturities Of Debt Investment Securities [Line Items]
Held to maturity, under 1 year, amortized cost	8,681
Held to maturity, under 1 year, fair value	8,531
Held to maturity, 1 to 5 years, amortized cost	10,239
Held to maturity, 1 to 5 years, fair value	9,769
Held to maturity, 6 to 10 years, amortized cost	6,130
Held to maturity, 6 to 10 years, fair value	5,309
Held to maturity, over 10 years, amortized cost	38,460
Held to maturity, over 10 years, fair value	33,254
Held to maturity, amortized cost	63,510
Investment securities held-to-maturity	$ 56,863