SEGMENT INFORMATION - Schedule of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
REVENUES
Premiums	$ 10.0	$ 7.0
Policy charges and fee income	112.0	117.0
Net investment income	70.0	76.0
Asset management and service fees	23.0	22.0
Other income	2.0	1.0
Investment gains (losses), net	(321.0)	165.0
TOTAL REVENUES	(104.0)	388.0
BENEFITS AND EXPENSES
Policyholder benefits and changes in fair value of insurance liabilities	(314.0)	340.0
Commission expense	23.0	23.0
General, administrative and other expenses	18.0	18.0
TOTAL BENEFITS AND EXPENSES	(273.0)	381.0
INCOME FROM OPERATIONS BEFORE INCOME TAXES	169.0	7.0
Less: Income tax expense	24.0	0.3
NET INCOME	145.0	7.0
Other comprehensive income (loss), before tax:
Changes in own-credit risk related to insurance liabilities	(13.0)	22.0
Less: Income tax expense	(3.0)	5.0
Other comprehensive income (loss), net of tax	(10.0)	17.0
COMPREHENSIVE INCOME	135.0	24.0
Retained Business
REVENUES
Premiums	10.0	7.0
Policy charges and fee income	112.0	117.0
Net investment income	56.0	56.0
Asset management and service fees	23.0	22.0
Other income	2.0	1.0
Investment gains (losses), net	(425.0)	30.0
TOTAL REVENUES	(222.0)	233.0
BENEFITS AND EXPENSES
Policyholder benefits and changes in fair value of insurance liabilities	(432.0)	185.0
Commission expense	23.0	23.0
General, administrative and other expenses	18.0	18.0
TOTAL BENEFITS AND EXPENSES	(391.0)	226.0
INCOME FROM OPERATIONS BEFORE INCOME TAXES	169.0	7.0
Less: Income tax expense	24.0	0.0
NET INCOME	145.0	7.0
Other comprehensive income (loss), before tax:
Changes in own-credit risk related to insurance liabilities	(13.0)	22.0
Less: Income tax expense	(3.0)	5.0
Other comprehensive income (loss), net of tax	(10.0)	17.0
COMPREHENSIVE INCOME	135.0	24.0
Ceded Business
REVENUES
Premiums	0.0	0.0
Policy charges and fee income	0.0	0.0
Net investment income	14.0	20.0
Asset management and service fees	0.0	0.0
Other income	0.0	0.0
Investment gains (losses), net	104.0	135.0
TOTAL REVENUES	118.0	155.0
BENEFITS AND EXPENSES
Policyholder benefits and changes in fair value of insurance liabilities	118.0	155.0
Commission expense	0.0	0.0
General, administrative and other expenses	0.0	0.0
TOTAL BENEFITS AND EXPENSES	118.0	155.0
INCOME FROM OPERATIONS BEFORE INCOME TAXES	0.0	0.0
Less: Income tax expense	0.0	0.0
NET INCOME	0.0	0.0
Other comprehensive income (loss), before tax:
Changes in own-credit risk related to insurance liabilities	0.0	0.0
Less: Income tax expense	0.0	0.0
Other comprehensive income (loss), net of tax	0.0	0.0
COMPREHENSIVE INCOME	$ 0.0	$ 0.0