Investment Securities - Summary of Unrealized Losses on Available-for-Sale Securities (Details) $ in Millions	Jun. 30, 2022 USD ($) Investment	Dec. 31, 2021 USD ($) Investment
Debt Securities, Available-for-sale [Line Items]
Number of investments in unrealized loss position \| Investment	767	475
Number of investments with unrealized losses greater than 12 months \| Investment	143	4
Fair Value of Investments, Less than 12 months	$ 21,263	$ 17,596
Unrealized Losses, Less than 12 months	1,283	304
Fair Value of Investments, 12 months or longer	4,921	163
Unrealized Losses, 12 months or longer	635	9
Fair Value of Investments	26,184	17,759
Unrealized Losses	1,918	313
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Fair Value of Investments, Less than 12 months	14,816	7,777
Unrealized Losses, Less than 12 months	656	70
Fair Value of Investments, 12 months or longer	1,576	0
Unrealized Losses, 12 months or longer	53	0
Fair Value of Investments	16,392	7,777
Unrealized Losses	709	70
U.S. agency debentures
Debt Securities, Available-for-sale [Line Items]
Fair Value of Investments, Less than 12 months	52	196
Unrealized Losses, Less than 12 months	2	4
Fair Value of Investments, 12 months or longer	70	0
Unrealized Losses, 12 months or longer	14	0
Fair Value of Investments	122	196
Unrealized Losses	16	4
Residential mortgage-backed securities \| Agency-issued mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Fair Value of Investments, Less than 12 months	4,306	8,280
Unrealized Losses, Less than 12 months	449	210
Fair Value of Investments, 12 months or longer	3,034	0
Unrealized Losses, 12 months or longer	526	0
Fair Value of Investments	7,340	8,280
Unrealized Losses	975	210
Residential mortgage-backed securities \| Agency-issued collateralized mortgage obligations—fixed rate
Debt Securities, Available-for-sale [Line Items]
Fair Value of Investments, Less than 12 months	723	740
Unrealized Losses, Less than 12 months	55	9
Fair Value of Investments, 12 months or longer	67	0
Unrealized Losses, 12 months or longer	8	0
Fair Value of Investments	790	740
Unrealized Losses	63	9
Agency-issued commercial mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Fair Value of Investments, Less than 12 months	1,366	603
Unrealized Losses, Less than 12 months	121	11
Fair Value of Investments, 12 months or longer	174	163
Unrealized Losses, 12 months or longer	34	9
Fair Value of Investments	1,540	766
Unrealized Losses	$ 155	$ 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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