INVESTMENTS - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale [Line Items]
Non-accrual status	$ 3,000,000	$ 2,000,000
Decrease in collateral securities held	63,000,000
Increase in securities received as collateral	15,000,000
U.S. corporate public securities
Debt Securities, Available-for-Sale [Line Items]
Securities	1,121,000,000	967,000,000
Fair Value | U.S. corporate public securities
Debt Securities, Available-for-Sale [Line Items]
Securities	$ 1,166,000,000	$ 999,000,000