Investment Securities - Schedule of Gross Pre-Tax Unrealized Losses on Investment Securities (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	$ 9,191	$ 19,429
Available for sale, gross unrealized losses less than 12 months	132	369
Available for sale, fair value 12 months or longer	30,717	18,093
Available for sale, gross unrealized losses 12 months or longer	1,053	924
Available for sale, fair value total	39,908	37,522
Available for sale, gross unrealized losses total	1,185	1,293
Direct obligations
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	590	1,337
Available for sale, gross unrealized losses less than 12 months	4	15
Available for sale, fair value 12 months or longer	5,777	5,745
Available for sale, gross unrealized losses 12 months or longer	183	246
Available for sale, fair value total	6,367	7,082
Available for sale, gross unrealized losses total	187	261
Mortgage-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	1,655	5,524
Available for sale, gross unrealized losses less than 12 months	22	130
Available for sale, fair value 12 months or longer	7,128	2,815
Available for sale, gross unrealized losses 12 months or longer	205	130
Available for sale, fair value total	8,783	8,339
Available for sale, gross unrealized losses total	227	260
Total U.S. Treasury and federal agencies
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	2,245	6,861
Available for sale, gross unrealized losses less than 12 months	26	145
Available for sale, fair value 12 months or longer	12,905	8,560
Available for sale, gross unrealized losses 12 months or longer	388	376
Available for sale, fair value total	15,150	15,421
Available for sale, gross unrealized losses total	414	521
Mortgage-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	150	1,278
Available for sale, gross unrealized losses less than 12 months	1	15
Available for sale, fair value 12 months or longer	1,076	272
Available for sale, gross unrealized losses 12 months or longer	11	4
Available for sale, fair value total	1,226	1,550
Available for sale, gross unrealized losses total	12	19
Asset-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	49	859
Available for sale, gross unrealized losses less than 12 months	0	11
Available for sale, fair value 12 months or longer	1,308	765
Available for sale, gross unrealized losses 12 months or longer	20	16
Available for sale, fair value total	1,357	1,624
Available for sale, gross unrealized losses total	20	27
Non-U.S. sovereign, supranational and non-U.S. agency
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	5,567	6,750
Available for sale, gross unrealized losses less than 12 months	84	108
Available for sale, fair value 12 months or longer	10,251	5,800
Available for sale, gross unrealized losses 12 months or longer	388	316
Available for sale, fair value total	15,818	12,550
Available for sale, gross unrealized losses total	472	424
Other
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	366	771
Available for sale, gross unrealized losses less than 12 months	11	27
Available for sale, fair value 12 months or longer	1,711	1,233
Available for sale, gross unrealized losses 12 months or longer	153	137
Available for sale, fair value total	2,077	2,004
Available for sale, gross unrealized losses total	164	164
Total non-U.S. debt securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	6,132	9,658
Available for sale, gross unrealized losses less than 12 months	96	161
Available for sale, fair value 12 months or longer	14,346	8,070
Available for sale, gross unrealized losses 12 months or longer	572	473
Available for sale, fair value total	20,478	17,728
Available for sale, gross unrealized losses total	668	634
Student loans
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	82	89
Available for sale, gross unrealized losses less than 12 months	1	1
Available for sale, fair value 12 months or longer	0	0
Available for sale, gross unrealized losses 12 months or longer	0	0
Available for sale, fair value total	82	89
Available for sale, gross unrealized losses total	1	1
Collateralized loan obligations
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	260	1,577
Available for sale, gross unrealized losses less than 12 months	1	27
Available for sale, fair value 12 months or longer	2,059	710
Available for sale, gross unrealized losses 12 months or longer	24	12
Available for sale, fair value total	2,319	2,287
Available for sale, gross unrealized losses total	25	39
Non-agency CMBS and RMBS
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	39	193
Available for sale, gross unrealized losses less than 12 months	1	6
Available for sale, fair value 12 months or longer	209	3
Available for sale, gross unrealized losses 12 months or longer	4	0
Available for sale, fair value total	248	196
Available for sale, gross unrealized losses total	5	6
Other
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months		88
Available for sale, gross unrealized losses less than 12 months		2
Available for sale, fair value 12 months or longer		0
Available for sale, gross unrealized losses 12 months or longer		0
Available for sale, fair value total		88
Available for sale, gross unrealized losses total		2
Total asset-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	381	1,947
Available for sale, gross unrealized losses less than 12 months	3	36
Available for sale, fair value 12 months or longer	2,268	713
Available for sale, gross unrealized losses 12 months or longer	28	12
Available for sale, fair value total	2,649	2,660
Available for sale, gross unrealized losses total	31	48
State and political subdivisions
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	404	669
Available for sale, gross unrealized losses less than 12 months	4	12
Available for sale, fair value 12 months or longer	270	42
Available for sale, gross unrealized losses 12 months or longer	7	5
Available for sale, fair value total	674	711
Available for sale, gross unrealized losses total	11	17
Other U.S. debt securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	29	294
Available for sale, gross unrealized losses less than 12 months	3	15
Available for sale, fair value 12 months or longer	928	708
Available for sale, gross unrealized losses 12 months or longer	58	58
Available for sale, fair value total	957	1,002
Available for sale, gross unrealized losses total	$ 61	$ 73