COMMITMENTS AND CONTINGENCIES - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Long-Term Purchase Commitment [Line Items]
Committed capital	$ 568.7	$ 568.7
C.M. Life Insurance
Long-Term Purchase Commitment [Line Items]
Committed capital	5.0	5.0
Mass Mutual
Long-Term Purchase Commitment [Line Items]
Committed capital	$ 95.0	$ 95.0