Investment Securities - Summary of Unrealized Losses on Available-for-Sale Securities (Detail)	Dec. 31, 2022 USD ($) Investment	Dec. 31, 2021 USD ($) Investment
Investments, Unrealized Loss Position [Line Items]
Fair Value of Investments, Less than 12 months	$ 15,724,000,000	$ 17,596,000,000
Unrealized Losses, Less than 12 months (less than $1 million at December 31, 2020 for U.S. Treasury AFS)	(1,109,000,000)	(304,000,000)
Fair Value of Investments, 12 months or longer	10,344,000,000	163,000,000
Unrealized Losses, 12 months or longer	(1,424,000,000)	(9,000,000)
Fair Value of Investments	26,068,000,000	17,759,000,000
Unrealized Losses	$ (2,533,000,000)	$ (313,000,000)
Number of investments in unrealized loss position | Investment	810	475
Number of investments with unrealized losses greater than 12 months | Investment	346	4
Investments in our AFS securities portfolio past due	$ 0	$ 0
U.S. Treasury securities
Investments, Unrealized Loss Position [Line Items]
Fair Value of Investments, Less than 12 months	11,946,000,000	7,777,000,000
Unrealized Losses, Less than 12 months (less than $1 million at December 31, 2020 for U.S. Treasury AFS)	(717,000,000)	(70,000,000)
Fair Value of Investments, 12 months or longer	4,189,000,000	0
Unrealized Losses, 12 months or longer	(354,000,000)	0
Fair Value of Investments	16,135,000,000	7,777,000,000
Unrealized Losses	(1,071,000,000)	(70,000,000)
U.S. agency debentures
Investments, Unrealized Loss Position [Line Items]
Fair Value of Investments, Less than 12 months	0	196,000,000
Unrealized Losses, Less than 12 months (less than $1 million at December 31, 2020 for U.S. Treasury AFS)	0	(4,000,000)
Fair Value of Investments, 12 months or longer	101,000,000	0
Unrealized Losses, 12 months or longer	(19,000,000)	0
Fair Value of Investments	101,000,000	196,000,000
Unrealized Losses	(19,000,000)	(4,000,000)
Foreign government debt securities
Investments, Unrealized Loss Position [Line Items]
Fair Value of Investments, Less than 12 months	1,088,000,000
Unrealized Losses, Less than 12 months (less than $1 million at December 31, 2020 for U.S. Treasury AFS)	(121,000,000)
Fair Value of Investments, 12 months or longer	0
Unrealized Losses, 12 months or longer	0
Fair Value of Investments	1,088,000,000
Unrealized Losses	(121,000,000)
Agency-issued MBS
Investments, Unrealized Loss Position [Line Items]
Fair Value of Investments, Less than 12 months	1,744,000,000	8,280,000,000
Unrealized Losses, Less than 12 months (less than $1 million at December 31, 2020 for U.S. Treasury AFS)	(203,000,000)	(210,000,000)
Fair Value of Investments, 12 months or longer	4,859,000,000	0
Unrealized Losses, 12 months or longer	(895,000,000)	0
Fair Value of Investments	6,603,000,000	8,280,000,000
Unrealized Losses	(1,098,000,000)	(210,000,000)
Agency-issued CMO—fixed rate
Investments, Unrealized Loss Position [Line Items]
Fair Value of Investments, Less than 12 months	136,000,000	740,000,000
Unrealized Losses, Less than 12 months (less than $1 million at December 31, 2020 for U.S. Treasury AFS)	(11,000,000)	(9,000,000)
Fair Value of Investments, 12 months or longer	542,000,000	0
Unrealized Losses, 12 months or longer	(73,000,000)	0
Fair Value of Investments	678,000,000	740,000,000
Unrealized Losses	(84,000,000)	(9,000,000)
Agency-issued CMBS
Investments, Unrealized Loss Position [Line Items]
Fair Value of Investments, Less than 12 months	810,000,000	603,000,000
Unrealized Losses, Less than 12 months (less than $1 million at December 31, 2020 for U.S. Treasury AFS)	(57,000,000)	(11,000,000)
Fair Value of Investments, 12 months or longer	653,000,000	163,000,000
Unrealized Losses, 12 months or longer	(83,000,000)	(9,000,000)
Fair Value of Investments	1,463,000,000	766,000,000
Unrealized Losses	$ (140,000,000)	$ (20,000,000)