Investment Securities - Schedule of Gross Pre-Tax Unrealized Losses on Investment Securities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	$ 10,198	$ 6,383
Available for sale, gross unrealized losses less than 12 months	37	16
Available for sale, fair value 12 months or longer	20,305	22,572
Available for sale, gross unrealized losses 12 months or longer	426	520
Available for sale, fair value total	30,503	28,955
Available for sale, gross unrealized losses total	463	536
Direct obligations
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	2,359	333
Available for sale, gross unrealized losses less than 12 months	8	2
Available for sale, fair value 12 months or longer	5,403	5,416
Available for sale, gross unrealized losses 12 months or longer	136	163
Available for sale, fair value total	7,762	5,749
Available for sale, gross unrealized losses total	144	165
Mortgage-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	1,321	961
Available for sale, gross unrealized losses less than 12 months	11	6
Available for sale, fair value 12 months or longer	6,402	6,512
Available for sale, gross unrealized losses 12 months or longer	138	158
Available for sale, fair value total	7,723	7,473
Available for sale, gross unrealized losses total	149	164
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	3,680	1,294
Available for sale, gross unrealized losses less than 12 months	19	8
Available for sale, fair value 12 months or longer	11,805	11,928
Available for sale, gross unrealized losses 12 months or longer	274	321
Available for sale, fair value total	15,485	13,222
Available for sale, gross unrealized losses total	293	329
Mortgage-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	310	424
Available for sale, gross unrealized losses less than 12 months	0	1
Available for sale, fair value 12 months or longer	584	719
Available for sale, gross unrealized losses 12 months or longer	4	6
Available for sale, fair value total	894	1,143
Available for sale, gross unrealized losses total	4	7
Asset-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	126	358
Available for sale, gross unrealized losses less than 12 months	0	0
Available for sale, fair value 12 months or longer	917	1,052
Available for sale, gross unrealized losses 12 months or longer	7	13
Available for sale, fair value total	1,043	1,410
Available for sale, gross unrealized losses total	7	13
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	5,579	3,972
Available for sale, gross unrealized losses less than 12 months	16	7
Available for sale, fair value 12 months or longer	5,415	5,788
Available for sale, gross unrealized losses 12 months or longer	103	125
Available for sale, fair value total	10,994	9,760
Available for sale, gross unrealized losses total	119	132
Other
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	66	50
Available for sale, gross unrealized losses less than 12 months	0	0
Available for sale, fair value 12 months or longer	720	893
Available for sale, gross unrealized losses 12 months or longer	29	37
Available for sale, fair value total	786	943
Available for sale, gross unrealized losses total	29	37
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	6,081	4,804
Available for sale, gross unrealized losses less than 12 months	16	8
Available for sale, fair value 12 months or longer	7,636	8,452
Available for sale, gross unrealized losses 12 months or longer	143	181
Available for sale, fair value total	13,717	13,256
Available for sale, gross unrealized losses total	159	189
Collateralized loan obligations
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	227	183
Available for sale, gross unrealized losses less than 12 months	0	0
Available for sale, fair value 12 months or longer	432	1,605
Available for sale, gross unrealized losses 12 months or longer	2	6
Available for sale, fair value total	659	1,788
Available for sale, gross unrealized losses total	2	6
Non-agency CMBS and RMBS
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	0	35
Available for sale, gross unrealized losses less than 12 months	0	0
Available for sale, fair value 12 months or longer	119	180
Available for sale, gross unrealized losses 12 months or longer	1	3
Available for sale, fair value total	119	215
Available for sale, gross unrealized losses total	1	3
Total asset-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	227	218
Available for sale, gross unrealized losses less than 12 months	0	0
Available for sale, fair value 12 months or longer	551	1,785
Available for sale, gross unrealized losses 12 months or longer	3	9
Available for sale, fair value total	778	2,003
Available for sale, gross unrealized losses total	3	9
State and political subdivisions
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	210	64
Available for sale, gross unrealized losses less than 12 months	2	0
Available for sale, fair value 12 months or longer	130	104
Available for sale, gross unrealized losses 12 months or longer	1	1
Available for sale, fair value total	340	168
Available for sale, gross unrealized losses total	3	1
Other U.S. debt securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	0	3
Available for sale, gross unrealized losses less than 12 months	0	0
Available for sale, fair value 12 months or longer	183	303
Available for sale, gross unrealized losses 12 months or longer	5	8
Available for sale, fair value total	183	306
Available for sale, gross unrealized losses total	$ 5	$ 8

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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