Investment Securities - Schedule of Contractual Maturities of Debt Securities (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	$ 7,040
Available for sale, under 1 year, fair value	6,952
Available for sale, 1 to 5 years, amortized cost	18,477
Available for sale, 1 to 5 years, fair value	17,532
Available for sale, 6 to 10 years, amortized cost	12,569
Available for sale, 6 to 10 years, fair value	12,362
Available for sale, over 10 years, amortized cost	4,277
Available for sale, over 10 years, fair value	4,140
Available for sale, amortized cost	42,363	$ 73,440
Available for sale, fair value	40,986	73,399
Held to maturity, amortized cost	65,232	42,430
Investment securities held-to-maturity	58,320	42,271
Direct obligations
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	1,919
Available for sale, under 1 year, fair value	1,883
Available for sale, 1 to 5 years, amortized cost	5,703
Available for sale, 1 to 5 years, fair value	5,433
Available for sale, 6 to 10 years, amortized cost	528
Available for sale, 6 to 10 years, fair value	540
Available for sale, over 10 years, amortized cost	0
Available for sale, over 10 years, fair value	0
Available for sale, amortized cost	8,150	18,111
Available for sale, fair value	7,856	17,939
Held to maturity, under 1 year, amortized cost	97
Held to maturity, under 1 year, fair value	96
Held to maturity, 1 to 5 years, amortized cost	11,502
Held to maturity, 1 to 5 years, fair value	11,152
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	14
Held to maturity, over 10 years, fair value	14
Held to maturity, amortized cost	11,637	2,170
Investment securities held-to-maturity	11,284	2,180
Mortgage-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	53
Available for sale, under 1 year, fair value	52
Available for sale, 1 to 5 years, amortized cost	502
Available for sale, 1 to 5 years, fair value	498
Available for sale, 6 to 10 years, amortized cost	7,239
Available for sale, 6 to 10 years, fair value	7,111
Available for sale, over 10 years, amortized cost	1,824
Available for sale, over 10 years, fair value	1,742
Available for sale, amortized cost	9,618	18,154
Available for sale, fair value	9,403	18,208
Held to maturity, under 1 year, amortized cost	158
Held to maturity, under 1 year, fair value	143
Held to maturity, 1 to 5 years, amortized cost	622
Held to maturity, 1 to 5 years, fair value	584
Held to maturity, 6 to 10 years, amortized cost	4,549
Held to maturity, 6 to 10 years, fair value	3,756
Held to maturity, over 10 years, amortized cost	37,638
Held to maturity, over 10 years, fair value	32,277
Held to maturity, amortized cost	42,967	33,481
Investment securities held-to-maturity	36,760	33,265
Total U.S. Treasury and federal agencies
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	1,972
Available for sale, under 1 year, fair value	1,935
Available for sale, 1 to 5 years, amortized cost	6,205
Available for sale, 1 to 5 years, fair value	5,931
Available for sale, 6 to 10 years, amortized cost	7,767
Available for sale, 6 to 10 years, fair value	7,651
Available for sale, over 10 years, amortized cost	1,824
Available for sale, over 10 years, fair value	1,742
Available for sale, amortized cost	17,768	36,265
Available for sale, fair value	17,259	36,147
Held to maturity, under 1 year, amortized cost	255
Held to maturity, under 1 year, fair value	239
Held to maturity, 1 to 5 years, amortized cost	12,124
Held to maturity, 1 to 5 years, fair value	11,736
Held to maturity, 6 to 10 years, amortized cost	4,573
Held to maturity, 6 to 10 years, fair value	3,778
Held to maturity, over 10 years, amortized cost	37,652
Held to maturity, over 10 years, fair value	32,291
Held to maturity, amortized cost	54,604	35,651
Investment securities held-to-maturity	48,044	35,445
Mortgage-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	123
Available for sale, under 1 year, fair value	123
Available for sale, 1 to 5 years, amortized cost	339
Available for sale, 1 to 5 years, fair value	336
Available for sale, 6 to 10 years, amortized cost	20
Available for sale, 6 to 10 years, fair value	20
Available for sale, over 10 years, amortized cost	1,198
Available for sale, over 10 years, fair value	1,183
Available for sale, amortized cost	1,680	1,986
Available for sale, fair value	1,662	1,995
Asset-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	272
Available for sale, under 1 year, fair value	266
Available for sale, 1 to 5 years, amortized cost	653
Available for sale, 1 to 5 years, fair value	642
Available for sale, 6 to 10 years, amortized cost	422
Available for sale, 6 to 10 years, fair value	415
Available for sale, over 10 years, amortized cost	324
Available for sale, over 10 years, fair value	317
Available for sale, amortized cost	1,671	2,087
Available for sale, fair value	1,640	2,087
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	3,929
Available for sale, under 1 year, fair value	3,894
Available for sale, 1 to 5 years, amortized cost	7,653
Available for sale, 1 to 5 years, fair value	7,244
Available for sale, 6 to 10 years, amortized cost	2,560
Available for sale, 6 to 10 years, fair value	2,536
Available for sale, over 10 years, amortized cost	0
Available for sale, over 10 years, fair value	0
Available for sale, amortized cost	14,142	23,533
Available for sale, fair value	13,674	23,547
Held to maturity, under 1 year, amortized cost	638
Held to maturity, under 1 year, fair value	632
Held to maturity, 1 to 5 years, amortized cost	4,945
Held to maturity, 1 to 5 years, fair value	4,722
Held to maturity, 6 to 10 years, amortized cost	558
Held to maturity, 6 to 10 years, fair value	519
Held to maturity, over 10 years, amortized cost	0
Held to maturity, over 10 years, fair value	0
Held to maturity, amortized cost	6,141	1,564
Investment securities held-to-maturity	5,873	1,555
Other
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	241
Available for sale, under 1 year, fair value	238
Available for sale, 1 to 5 years, amortized cost	1,864
Available for sale, 1 to 5 years, fair value	1,715
Available for sale, 6 to 10 years, amortized cost	130
Available for sale, 6 to 10 years, fair value	110
Available for sale, over 10 years, amortized cost	27
Available for sale, over 10 years, fair value	21
Available for sale, amortized cost	2,262	3,113
Available for sale, fair value	2,084	3,098
Total non-U.S. debt securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	4,565
Available for sale, under 1 year, fair value	4,521
Available for sale, 1 to 5 years, amortized cost	10,509
Available for sale, 1 to 5 years, fair value	9,937
Available for sale, 6 to 10 years, amortized cost	3,132
Available for sale, 6 to 10 years, fair value	3,081
Available for sale, over 10 years, amortized cost	1,549
Available for sale, over 10 years, fair value	1,521
Available for sale, amortized cost	19,755	30,719
Available for sale, fair value	19,060	30,727
Held to maturity, under 1 year, amortized cost	638
Held to maturity, under 1 year, fair value	632
Held to maturity, 1 to 5 years, amortized cost	4,945
Held to maturity, 1 to 5 years, fair value	4,722
Held to maturity, 6 to 10 years, amortized cost	558
Held to maturity, 6 to 10 years, fair value	519
Held to maturity, over 10 years, amortized cost	0
Held to maturity, over 10 years, fair value	0
Held to maturity, amortized cost	6,141	1,564
Investment securities held-to-maturity	5,873	1,555
Student loans
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	51
Available for sale, under 1 year, fair value	51
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	83
Available for sale, over 10 years, fair value	82
Available for sale, amortized cost	134	209
Available for sale, fair value	133	211
Held to maturity, under 1 year, amortized cost	315
Held to maturity, under 1 year, fair value	304
Held to maturity, 1 to 5 years, amortized cost	12
Held to maturity, 1 to 5 years, fair value	12
Held to maturity, 6 to 10 years, amortized cost	989
Held to maturity, 6 to 10 years, fair value	973
Held to maturity, over 10 years, amortized cost	2,922
Held to maturity, over 10 years, fair value	2,846
Held to maturity, amortized cost	4,238	4,908
Investment securities held-to-maturity	4,135	4,942
Collateralized loan obligations
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	164
Available for sale, under 1 year, fair value	161
Available for sale, 1 to 5 years, amortized cost	422
Available for sale, 1 to 5 years, fair value	413
Available for sale, 6 to 10 years, amortized cost	1,240
Available for sale, 6 to 10 years, fair value	1,214
Available for sale, over 10 years, amortized cost	545
Available for sale, over 10 years, fair value	529
Available for sale, amortized cost	2,371	2,155
Available for sale, fair value	2,317	2,155
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	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	220
Available for sale, over 10 years, fair value	215
Available for sale, amortized cost	220	52
Available for sale, fair value	215	52
Held to maturity, under 1 year, amortized cost	176
Held to maturity, under 1 year, fair value	183
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	73
Held to maturity, over 10 years, fair value	85
Held to maturity, amortized cost	249	307
Investment securities held-to-maturity	268	329
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	88
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	88	91
Total asset-backed securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	215
Available for sale, under 1 year, fair value	212
Available for sale, 1 to 5 years, amortized cost	512
Available for sale, 1 to 5 years, fair value	501
Available for sale, 6 to 10 years, amortized cost	1,240
Available for sale, 6 to 10 years, fair value	1,214
Available for sale, over 10 years, amortized cost	848
Available for sale, over 10 years, fair value	826
Available for sale, amortized cost	2,815	2,506
Available for sale, fair value	2,753	2,509
Held to maturity, under 1 year, amortized cost	491
Held to maturity, under 1 year, fair value	487
Held to maturity, 1 to 5 years, amortized cost	12
Held to maturity, 1 to 5 years, fair value	12
Held to maturity, 6 to 10 years, amortized cost	989
Held to maturity, 6 to 10 years, fair value	973
Held to maturity, over 10 years, amortized cost	2,995
Held to maturity, over 10 years, fair value	2,931
Held to maturity, amortized cost	4,487	5,215
Investment securities held-to-maturity	4,403	5,271
State and political subdivisions
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	197
Available for sale, under 1 year, fair value	195
Available for sale, 1 to 5 years, amortized cost	309
Available for sale, 1 to 5 years, fair value	299
Available for sale, 6 to 10 years, amortized cost	390
Available for sale, 6 to 10 years, fair value	379
Available for sale, over 10 years, amortized cost	56
Available for sale, over 10 years, fair value	51
Available for sale, amortized cost	952	1,216
Available for sale, fair value	924	1,272
Other U.S. debt securities
Contractual Maturities Of Debt Investment Securities [Line Items]
Available for sale, under 1 year, amortized cost	91
Available for sale, under 1 year, fair value	89
Available for sale, 1 to 5 years, amortized cost	942
Available for sale, 1 to 5 years, fair value	864
Available for sale, 6 to 10 years, amortized cost	40
Available for sale, 6 to 10 years, fair value	37
Available for sale, over 10 years, amortized cost	0
Available for sale, over 10 years, fair value	0
Available for sale, amortized cost	1,073	2,734
Available for sale, fair value	990	$ 2,744
Total
Contractual Maturities Of Debt Investment Securities [Line Items]
Held to maturity, under 1 year, amortized cost	1,384
Held to maturity, under 1 year, fair value	1,358
Held to maturity, 1 to 5 years, amortized cost	17,081
Held to maturity, 1 to 5 years, fair value	16,470
Held to maturity, 6 to 10 years, amortized cost	6,120
Held to maturity, 6 to 10 years, fair value	5,270
Held to maturity, over 10 years, amortized cost	40,647
Held to maturity, over 10 years, fair value	35,222
Held to maturity, amortized cost	65,232
Investment securities held-to-maturity	$ 58,320