INVESTMENTS - Fixed Maturities Available-for-sale (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Available-For-Sale Securities, Continuous Unrealized Loss Position [Line Items]
Less than 12 months, fair value	$ 2,392	$ 934
Less than 12 months, gross unrealized losses	23	9
12 months or longer, fair value	2,118	2,038
12 Months or Longer, gross unrealized Losses	327	295
Total fair value	4,510	2,972
Total gross unrealized losses	350	304
Corporate
Available-For-Sale Securities, Continuous Unrealized Loss Position [Line Items]
Less than 12 months, fair value	1,237	505
Less than 12 months, gross unrealized losses	16	7
12 months or longer, fair value	1,974	1,900
12 Months or Longer, gross unrealized Losses	301	269
Total fair value	3,211	2,405
Total gross unrealized losses	317	276
U.S. Treasury, government and agency
Available-For-Sale Securities, Continuous Unrealized Loss Position [Line Items]
Less than 12 months, fair value	0	0
Less than 12 months, gross unrealized losses	0	0
12 months or longer, fair value	8	8
12 Months or Longer, gross unrealized Losses	1	0
Total fair value	8	8
Total gross unrealized losses	1	0
States and political subdivisions
Available-For-Sale Securities, Continuous Unrealized Loss Position [Line Items]
Less than 12 months, fair value	0	0
Less than 12 months, gross unrealized losses	0	0
12 months or longer, fair value	32	33
12 Months or Longer, gross unrealized Losses	8	7
Total fair value	32	33
Total gross unrealized losses	8	7
Foreign governments
Available-For-Sale Securities, Continuous Unrealized Loss Position [Line Items]
Less than 12 months, fair value	25	7
Less than 12 months, gross unrealized losses	1	1
12 months or longer, fair value	4	4
12 Months or Longer, gross unrealized Losses	0	0
Total fair value	29	11
Total gross unrealized losses	1	1
Residential mortgage-backed
Available-For-Sale Securities, Continuous Unrealized Loss Position [Line Items]
Less than 12 months, fair value	396	103
Less than 12 months, gross unrealized losses	4	0
12 months or longer, fair value	19	9
12 Months or Longer, gross unrealized Losses	4	4
Total fair value	415	112
Total gross unrealized losses	8	4
Asset-backed
Available-For-Sale Securities, Continuous Unrealized Loss Position [Line Items]
Less than 12 months, fair value	733	290
Less than 12 months, gross unrealized losses	2	1
12 months or longer, fair value	21	23
12 Months or Longer, gross unrealized Losses	1	1
Total fair value	754	313
Total gross unrealized losses	3	2
Commercial mortgage-backed
Available-For-Sale Securities, Continuous Unrealized Loss Position [Line Items]
Less than 12 months, fair value	1	29
Less than 12 months, gross unrealized losses	0	0
12 months or longer, fair value	60	61
12 Months or Longer, gross unrealized Losses	12	14
Total fair value	61	90
Total gross unrealized losses	$ 12	$ 14