SECURITIES - Schedule of Amortized Cost and Fair Value of Securities, by Contractual Maturities (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Amortized Cost
Available for sale, due in one year or less, amortized cost	$ 162
Available for sale, due after one year but within five years, amortized cost	482
Available for sale, due after five years but within ten years, amortized cost	21
Available for sale, due after ten years, amortized cost	25
Available for sale, with contractual maturities, amortized cost	690
Amortized Cost	3,620	$ 3,460
Fair Value
Available for sale, due in one year or less, fair value	161
Available for sale, due after one year but within five years, fair value	481
Available for sale, due after five years but within ten years, fair value	20
Available for sale, due after ten years, fair value	24
Available for sale, with contractual maturities, fair value	686
Fair Value	3,466	3,254
Amortized Cost
Held to maturity, due in one year or less, amortized cost	34
Held to maturity, due after one year but within five years, amortized cost	70
Held to maturity, due after five years but within ten years, amortized cost	223
Held to maturity, due after ten years, amortized cost	711
Held to maturity, with contractual maturities, amortized cost	1,038
Amortized Cost	3,979	3,911
Fair Value
Held to maturity, due in one year or less, fair value	34
Held to maturity, due after one year but within five years, fair value	65
Held to maturity, due after five years but within ten years, fair value	207
Held to maturity, due after ten years, fair value	629
Held to maturity, with contractual maturities, fair value	935
Fair Value	3,644	3,593
Agency MBS
Amortized Cost
Available-for-sale, amortized cost	714
Amortized Cost	714	814
Fair Value
Available for sale, fair value	694
Fair Value	694	752
Amortized Cost
Held to maturity, amortized cost	901
Amortized Cost	901	1,057
Fair Value
Held to maturity, fair value	806
Fair Value	806	958
Agency collateralized mortgage obligations
Amortized Cost
Available-for-sale, amortized cost	796
Amortized Cost	796	946
Fair Value
Available for sale, fair value	698
Fair Value	698	832
Amortized Cost
Held to maturity, amortized cost	714
Amortized Cost	714	824
Fair Value
Held to maturity, fair value	619
Fair Value	619	720
Agency commercial MBS
Amortized Cost
Available-for-sale, amortized cost	1,420
Amortized Cost	1,420	905
Fair Value
Available for sale, fair value	1,388
Fair Value	1,388	884
Amortized Cost
Held to maturity, amortized cost	1,326
Amortized Cost	1,326	929
Fair Value
Held to maturity, fair value	1,284
Fair Value	$ 1,284	$ 890