INVESTMENTS - Investment Gains (Losses), Net (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Net Investment Income [Line Items]
Investment gains (losses), net	$ (508)	$ (348)	$ (644)	$ (912)
Excluding Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	(365)	(348)	(465)	(912)
Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	(143)	0	(179)	0
Fixed maturities
Net Investment Income [Line Items]
Investment gains (losses), net	(445)	(327)	(565)	(881)
Fixed maturities | Excluding Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	(344)	(327)	(430)	(881)
Fixed maturities | Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	(101)	0	(135)	0
Mortgage loans on real estate
Net Investment Income [Line Items]
Investment gains (losses), net	(64)	(19)	(80)	(21)
Mortgage loans on real estate | Excluding Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	(22)	(19)	(36)	(21)
Mortgage loans on real estate | Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	(42)	0	(44)	0
Other
Net Investment Income [Line Items]
Investment gains (losses), net	1	(2)	1	(10)
Other | Excluding Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	1	(2)	1	(10)
Other | Funds Withheld and NI Modco
Net Investment Income [Line Items]
Investment gains (losses), net	$ 0	$ 0	$ 0	$ 0