SECURITIES - Summaries of Fair Values and Unrealized Losses of Securities, Segregated by Length of Impairment (Detail) $ in Millions	Dec. 31, 2022 USD ($) security	Dec. 31, 2021 USD ($) security
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions \| security	198	60
Debt securities, available-for-sale, 12 months or longer, number of positions \| security	67	14
Debt securities, available-for-sale, number of positions \| security	265	74
Debt securities, available-for-sale, less than 12 months	$ 1,868	$ 1,679
Debt securities, available-for-sale, 12 months or longer	1,343	102
Debt securities, available-for-sale, unrealized loss position	3,211	1,781
Debt securities, available-for-sale, less than 12 months, accumulated loss	(138)	(23)
Debt securities, available-for-sale, 12 months or longer, accumulated loss	(210)	(3)
Debt securities, available-for-sale, accumulated loss	$ (348)	$ (26)
U.S. Treasury
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions \| security	3	3
Debt securities, available-for-sale, 12 months or longer, number of positions \| security	3	0
Debt securities, available-for-sale, number of positions \| security	6	3
Debt securities, available-for-sale, less than 12 months	$ 120	$ 151
Debt securities, available-for-sale, 12 months or longer	137	0
Debt securities, available-for-sale, unrealized loss position	257	151
Debt securities, available-for-sale, less than 12 months, accumulated loss	(7)	(1)
Debt securities, available-for-sale, 12 months or longer, accumulated loss	(14)	0
Debt securities, available-for-sale, accumulated loss	$ (21)	$ (1)
U.S. government agencies
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions \| security	6	3
Debt securities, available-for-sale, 12 months or longer, number of positions \| security	8	9
Debt securities, available-for-sale, number of positions \| security	14	12
Debt securities, available-for-sale, less than 12 months	$ 46	$ 22
Debt securities, available-for-sale, 12 months or longer	4	8
Debt securities, available-for-sale, unrealized loss position	50	30
Debt securities, available-for-sale, less than 12 months, accumulated loss	0	0
Debt securities, available-for-sale, 12 months or longer, accumulated loss	0	0
Debt securities, available-for-sale, accumulated loss	$ 0	$ 0
U.S. government-sponsored entities
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions \| security	9	3
Debt securities, available-for-sale, 12 months or longer, number of positions \| security	4	1
Debt securities, available-for-sale, number of positions \| security	13	4
Debt securities, available-for-sale, less than 12 months	$ 150	$ 99
Debt securities, available-for-sale, 12 months or longer	112	24
Debt securities, available-for-sale, unrealized loss position	262	123
Debt securities, available-for-sale, less than 12 months, accumulated loss	(8)	(1)
Debt securities, available-for-sale, 12 months or longer, accumulated loss	(13)	(1)
Debt securities, available-for-sale, accumulated loss	$ (21)	$ (2)
Agency mortgage-backed securities
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions \| security	104	13
Debt securities, available-for-sale, 12 months or longer, number of positions \| security	13	0
Debt securities, available-for-sale, number of positions \| security	117	13
Debt securities, available-for-sale, less than 12 months	$ 773	$ 599
Debt securities, available-for-sale, 12 months or longer	455	0
Debt securities, available-for-sale, unrealized loss position	1,228	599
Debt securities, available-for-sale, less than 12 months, accumulated loss	(58)	(4)
Debt securities, available-for-sale, 12 months or longer, accumulated loss	(70)	0
Debt securities, available-for-sale, accumulated loss	$ (128)	$ (4)
Agency collateralized mortgage obligations
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions \| security	49	23
Debt securities, available-for-sale, 12 months or longer, number of positions \| security	23	3
Debt securities, available-for-sale, number of positions \| security	72	26
Debt securities, available-for-sale, less than 12 months	$ 455	$ 659
Debt securities, available-for-sale, 12 months or longer	517	68
Debt securities, available-for-sale, unrealized loss position	972	727
Debt securities, available-for-sale, less than 12 months, accumulated loss	(42)	(15)
Debt securities, available-for-sale, 12 months or longer, accumulated loss	(96)	(2)
Debt securities, available-for-sale, accumulated loss	$ (138)	$ (17)
Commercial mortgage-backed securities
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions \| security	16	5
Debt securities, available-for-sale, 12 months or longer, number of positions \| security	5	0
Debt securities, available-for-sale, number of positions \| security	21	5
Debt securities, available-for-sale, less than 12 months	$ 302	$ 125
Debt securities, available-for-sale, 12 months or longer	94	0
Debt securities, available-for-sale, unrealized loss position	396	125
Debt securities, available-for-sale, less than 12 months, accumulated loss	(21)	(2)
Debt securities, available-for-sale, 12 months or longer, accumulated loss	(14)	0
Debt securities, available-for-sale, accumulated loss	$ (35)	$ (2)
States of the U.S. and political subdivisions (municipals)
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions \| security	4	10
Debt securities, available-for-sale, 12 months or longer, number of positions \| security	10	0
Debt securities, available-for-sale, number of positions \| security	14	10
Debt securities, available-for-sale, less than 12 months	$ 7	$ 24
Debt securities, available-for-sale, 12 months or longer	22	0
Debt securities, available-for-sale, unrealized loss position	29	24
Debt securities, available-for-sale, less than 12 months, accumulated loss	(1)	0
Debt securities, available-for-sale, 12 months or longer, accumulated loss	(3)	0
Debt securities, available-for-sale, accumulated loss	$ (4)	$ 0
Other debt securities
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions \| security	7	0
Debt securities, available-for-sale, 12 months or longer, number of positions \| security	1	1
Debt securities, available-for-sale, number of positions \| security	8	1
Debt securities, available-for-sale, less than 12 months	$ 15	$ 0
Debt securities, available-for-sale, 12 months or longer	2	2
Debt securities, available-for-sale, unrealized loss position	17	2
Debt securities, available-for-sale, less than 12 months, accumulated loss	(1)	0
Debt securities, available-for-sale, 12 months or longer, accumulated loss	0	0
Debt securities, available-for-sale, accumulated loss	$ (1)	$ 0

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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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