SECURITIES - Schedule of Amortized Cost and Fair Value of Securities Held to Maturity (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 3,911	$ 4,087
Gross Unrealized Gains	8	3
Gross Unrealized Losses	(326)	(403)
Fair  Value	3,593	3,687
U.S. government agencies
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	1	1
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair  Value	1	1
U.S. government-sponsored entities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	68	52
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair  Value	68	52
Agency mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	1,057	1,178
Gross Unrealized Gains	2	0
Gross Unrealized Losses	(101)	(125)
Fair  Value	958	1,053
Agency collateralized mortgage obligations
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	824	953
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(104)	(120)
Fair  Value	720	833
Commercial mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	929	866
Gross Unrealized Gains	4	2
Gross Unrealized Losses	(43)	(50)
Fair  Value	890	818
States of the U.S. and political subdivisions (municipals)
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	1,017	1,025
Gross Unrealized Gains	2	1
Gross Unrealized Losses	(77)	(107)
Fair  Value	942	919
Other debt securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	15	12
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	(1)
Fair  Value	$ 14	$ 11