Investment Securities - Summary of Unrealized Losses on Available-for-Sale Securities (Details) $ in Millions	Sep. 30, 2022 USD ($) Investment	Dec. 31, 2021 USD ($) Investment
Debt Securities, Available-for-sale [Line Items]
Fair Value of Investments, Less than 12 months	$ 17,868	$ 17,596
Unrealized Losses, Less than 12 months	1,526	304
Fair Value of Investments, 12 months or longer	8,832	163
Unrealized Losses, 12 months or longer	1,265	9
Fair Value of Investments	26,700	17,759
Unrealized Losses	$ 2,791	$ 313
Number of investments in unrealized loss position \| Investment	804	475
Number of investments with unrealized losses greater than 12 months \| Investment	289	4
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Fair Value of Investments, Less than 12 months	$ 13,359	$ 7,777
Unrealized Losses, Less than 12 months	958	70
Fair Value of Investments, 12 months or longer	3,487	0
Unrealized Losses, 12 months or longer	238	0
Fair Value of Investments	16,846	7,777
Unrealized Losses	1,196	70
U.S. agency debentures
Debt Securities, Available-for-sale [Line Items]
Fair Value of Investments, Less than 12 months	20	196
Unrealized Losses, Less than 12 months	1	4
Fair Value of Investments, 12 months or longer	80	0
Unrealized Losses, 12 months or longer	19	0
Fair Value of Investments	100	196
Unrealized Losses	20	4
Foreign government debt securities
Debt Securities, Available-for-sale [Line Items]
Fair Value of Investments, Less than 12 months	913
Unrealized Losses, Less than 12 months	149
Fair Value of Investments, 12 months or longer	0
Unrealized Losses, 12 months or longer	0
Fair Value of Investments	913
Unrealized Losses	149
Agency-issued MBS
Debt Securities, Available-for-sale [Line Items]
Fair Value of Investments, Less than 12 months	2,236	8,280
Unrealized Losses, Less than 12 months	304	210
Fair Value of Investments, 12 months or longer	4,448	0
Unrealized Losses, 12 months or longer	896	0
Fair Value of Investments	6,684	8,280
Unrealized Losses	1,200	210
Agency-issued CMO—fixed rate
Debt Securities, Available-for-sale [Line Items]
Fair Value of Investments, Less than 12 months	534	740
Unrealized Losses, Less than 12 months	55	9
Fair Value of Investments, 12 months or longer	168	0
Unrealized Losses, 12 months or longer	23	0
Fair Value of Investments	702	740
Unrealized Losses	78	9
Agency-issued CMBS
Debt Securities, Available-for-sale [Line Items]
Fair Value of Investments, Less than 12 months	806	603
Unrealized Losses, Less than 12 months	59	11
Fair Value of Investments, 12 months or longer	649	163
Unrealized Losses, 12 months or longer	89	9
Fair Value of Investments	1,455	766
Unrealized Losses	$ 148	$ 20

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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