INVESTMENTS - Investment Gains (Losses), Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Net Investment Income [Line Items]
Investment gains (losses), net	$ (125)	$ (800)	$ (962)
Excluding Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	(61)	(555)	(962)
Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	(64)	(245)	0
Fixed maturities
Net Investment Income [Line Items]
Investment gains (losses), net	(61)	(652)	(885)
Fixed maturities | Excluding Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	(29)	(497)	(885)
Fixed maturities | Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	(32)	(155)	0
Mortgage loans on real estate
Net Investment Income [Line Items]
Investment gains (losses), net	(70)	(149)	(66)
Mortgage loans on real estate | Excluding Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	(38)	(59)	(66)
Mortgage loans on real estate | Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	(32)	(90)	0
Other equity investments
Net Investment Income [Line Items]
Investment gains (losses), net	0	0	0
Other equity investments | Excluding Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	0	0	0
Other equity investments | Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	0	0	0
Other
Net Investment Income [Line Items]
Investment gains (losses), net	6	1	(11)
Other | Excluding Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	6	1	(11)
Other | Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	$ 0	$ 0	$ 0