Investment Securities - Schedule of Gross Pre-Tax Unrealized Losses on Investment Securities (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	$ 8,133	$ 18,678
Available for sale, gross unrealized losses less than 12 months	35	136
Available for sale, fair value 12 months or longer	8,265	10,412
Available for sale, gross unrealized losses 12 months or longer	62	147
Available for sale, fair value total	16,398	29,090
Available for sale, gross unrealized losses total	97	283
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	2,023	11,855
Available for sale, gross unrealized losses less than 12 months	5	84
Available for sale, fair value 12 months or longer	6,081	6,795
Available for sale, gross unrealized losses 12 months or longer	54	122
Available for sale, fair value total	8,104	18,650
Available for sale, gross unrealized losses total	59	206
US Treasury and federal agencies, direct obligations
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	756	8,113
Available for sale, gross unrealized losses less than 12 months	2	25
Available for sale, fair value 12 months or longer	2,063	2,435
Available for sale, gross unrealized losses 12 months or longer	3	27
Available for sale, fair value total	2,819	10,548
Available for sale, gross unrealized losses total	5	52
US Treasury and federal agencies, mortgage-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	1,267	3,742
Available for sale, gross unrealized losses less than 12 months	3	59
Available for sale, fair value 12 months or longer	4,018	4,360
Available for sale, gross unrealized losses 12 months or longer	51	95
Available for sale, fair value total	5,285	8,102
Available for sale, gross unrealized losses total	54	154
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	5,042	6,124
Available for sale, gross unrealized losses less than 12 months	29	52
Available for sale, fair value 12 months or longer	2,184	3,542
Available for sale, gross unrealized losses 12 months or longer	8	24
Available for sale, fair value total	7,226	9,666
Available for sale, gross unrealized losses total	37	76
Non-U.S. debt securities, mortgage-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	617	730
Available for sale, gross unrealized losses less than 12 months	1	1
Available for sale, fair value 12 months or longer	73	225
Available for sale, gross unrealized losses 12 months or longer	0	0
Available for sale, fair value total	690	955
Available for sale, gross unrealized losses total	1	1
Non-U.S. debt securities, asset-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	425	387
Available for sale, gross unrealized losses less than 12 months	0	0
Available for sale, fair value 12 months or longer	168	506
Available for sale, gross unrealized losses 12 months or longer	1	2
Available for sale, fair value total	593	893
Available for sale, gross unrealized losses total	1	2
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	3,871	4,695
Available for sale, gross unrealized losses less than 12 months	28	49
Available for sale, fair value 12 months or longer	1,943	2,695
Available for sale, gross unrealized losses 12 months or longer	7	20
Available for sale, fair value total	5,814	7,390
Available for sale, gross unrealized losses total	35	69
Non-U.S. debt securities, other
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	129	312
Available for sale, gross unrealized losses less than 12 months	0	2
Available for sale, fair value 12 months or longer	0	116
Available for sale, gross unrealized losses 12 months or longer	0	2
Available for sale, fair value total	129	428
Available for sale, gross unrealized losses total	0	4
Asset-backed securities, 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
Available for sale, gross unrealized losses less than 12 months		0
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		0
Available for sale, gross unrealized losses total		0
Asset-backed securities, student loans
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months		12
Available for sale, gross unrealized losses less than 12 months		0
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		12
Available for sale, gross unrealized losses total		0
Asset-backed securities, collateralized loan obligations
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	1,068	684
Available for sale, gross unrealized losses less than 12 months	1	0
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	1,068	684
Available for sale, gross unrealized losses total	1	0
Total asset-backed securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months	1,068	696
Available for sale, gross unrealized losses less than 12 months	1	0
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	1,068	696
Available for sale, gross unrealized losses total	$ 1	0
State and political subdivisions
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months		0
Available for sale, gross unrealized losses less than 12 months		0
Available for sale, fair value 12 months or longer		26
Available for sale, gross unrealized losses 12 months or longer		0
Available for sale, fair value total		26
Available for sale, gross unrealized losses total		0
Other U.S. debt securities
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]
Available for sale, fair value less than 12 months		3
Available for sale, gross unrealized losses less than 12 months		0
Available for sale, fair value 12 months or longer		49
Available for sale, gross unrealized losses 12 months or longer		1
Available for sale, fair value total		52
Available for sale, gross unrealized losses total		$ 1

Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]

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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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Amount of accumulated unrealized loss on 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 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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