FAIR VALUE MEASUREMENTS - CHANGES IN VALUE OF EMBEDDED DERIVATIVES (Details) - Significant unobservable inputs  (Level 3) - Fixed Index Annuity Products - Fair value, Measurements, Recurring - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Liabilities:
Balance at beginning of the period	$ 1,724.1	$ 1,644.5
Premiums less benefits	61.4	103.1
Change in fair value, net	(488.5)	(23.5)
Balance at end of the period	$ 1,297.0	$ 1,724.1