INVESTMENTS - Summary of Components of Net Investment Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Debt Securities, Available-for-Sale [Line Items]
Gross investment income before adjustments	$ 252	$ 188	$ 444	$ 350
Funds held interest income (expense)	(1)	1	1	3
Interest income from Group	3	2	7	4
Gross investment income	253	190	453	357
Investment expenses	(11)	(14)	(21)	(24)
Net investment income	242	176	432	333
Fixed maturities
Debt Securities, Available-for-Sale [Line Items]
Gross investment income before adjustments	199	116	374	210
Equity securities
Debt Securities, Available-for-Sale [Line Items]
Gross investment income before adjustments	1	5	2	9
Short-term investments and cash
Debt Securities, Available-for-Sale [Line Items]
Gross investment income before adjustments	16	1	27	1
Limited partnerships
Debt Securities, Available-for-Sale [Line Items]
Gross investment income before adjustments	22	45	(1)	89
Dividends from preferred shares of affiliate
Debt Securities, Available-for-Sale [Line Items]
Gross investment income before adjustments	8	8	16	16
Other
Debt Securities, Available-for-Sale [Line Items]
Gross investment income before adjustments	$ 6	$ 14	$ 27	$ 26