INVESTMENTS - Schedule of Amortized Cost, Allowance for Credit Losses, Gross Unrealized Appreciation/(Depreciation) and Fair Value of Fixed Maturity Securities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Fixed maturity securities - available for sale
Fixed maturities, amortized cost	$ 28,568	$ 24,191
Allowance for Credit Losses	(48)	(54)	$ (30)
Unrealized Appreciation	358	81
Unrealized Depreciation	(1,137)	(1,982)
Fair Value	27,740	22,236
Fixed maturity securities - held to maturity
Amortized Cost	864	848
Allowance for Credit Losses	(8)	(9)	0
Unrealized Appreciation	12	3
Unrealized Depreciation	(13)	(22)
Fair Value	854	821
U.S. Treasury securities and obligations of U.S. government agencies and corporations
Fixed maturity securities - available for sale
Fixed maturities, amortized cost	1,045	1,334
Allowance for Credit Losses	0	0
Unrealized Appreciation	3	6
Unrealized Depreciation	(52)	(82)
Fair Value	996	1,257
Obligations of U.S. States and political subdivisions
Fixed maturity securities - available for sale
Fixed maturities, amortized cost	138	444
Allowance for Credit Losses	0	0
Unrealized Appreciation	1	2
Unrealized Depreciation	(11)	(32)
Fair Value	128	413
Corporate securities
Fixed maturity securities - available for sale
Fixed maturities, amortized cost	7,587	7,044
Allowance for Credit Losses	(47)	(45)	(19)
Unrealized Appreciation	135	31
Unrealized Depreciation	(322)	(561)
Fair Value	7,353	6,469
Fixed maturity securities - held to maturity
Amortized Cost	150	152
Allowance for Credit Losses	(2)	(2)	0
Unrealized Appreciation	1	0
Unrealized Depreciation	(3)	(6)
Fair Value	146	144
Asset-backed securities
Fixed maturity securities - available for sale
Fixed maturities, amortized cost	5,644	4,229
Allowance for Credit Losses	0	0	(8)
Unrealized Appreciation	25	5
Unrealized Depreciation	(51)	(171)
Fair Value	5,618	4,063
Fixed maturity securities - held to maturity
Amortized Cost	609	661
Allowance for Credit Losses	(5)	(6)	0
Unrealized Appreciation	4	2
Unrealized Depreciation	(10)	(15)
Fair Value	597	642
Commercial
Fixed maturity securities - available for sale
Fixed maturities, amortized cost	1,091	1,023
Allowance for Credit Losses	0	0
Unrealized Appreciation	1	0
Unrealized Depreciation	(92)	(105)
Fair Value	1,000	919
Fixed maturity securities - held to maturity
Amortized Cost	21	7
Allowance for Credit Losses	0	0
Unrealized Appreciation	0	0
Unrealized Depreciation	0	0
Fair Value	21	7
Agency residential
Fixed maturity securities - available for sale
Fixed maturities, amortized cost	4,869	3,382
Allowance for Credit Losses	0	0
Unrealized Appreciation	55	7
Unrealized Depreciation	(229)	(290)
Fair Value	4,695	3,099
Non-agency residential
Fixed maturity securities - available for sale
Fixed maturities, amortized cost	431	5
Allowance for Credit Losses	0	0
Unrealized Appreciation	14	0
Unrealized Depreciation	(2)	(1)
Fair Value	443	4
Foreign government securities
Fixed maturity securities - available for sale
Fixed maturities, amortized cost	2,042	1,586
Allowance for Credit Losses	0	0
Unrealized Appreciation	33	8
Unrealized Depreciation	(108)	(179)
Fair Value	1,967	1,415
Foreign corporate securities
Fixed maturity securities - available for sale
Fixed maturities, amortized cost	5,720	5,143
Allowance for Credit Losses	(1)	(10)	(3)
Unrealized Appreciation	92	23
Unrealized Depreciation	(271)	(562)
Fair Value	5,540	4,596
Fixed maturity securities - held to maturity
Amortized Cost	84	28
Allowance for Credit Losses	(1)	(1)	$ 0
Unrealized Appreciation	7	2
Unrealized Depreciation	0	0
Fair Value	$ 90	$ 28

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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