REINUSRANCE - Schedule of Reinsurance Included In Statements of Operations and Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2021
Premiums:
Direct	$ 9,000	$ 22,000	$ 31,000	$ 24,000
Assumed	0			16,000
Ceded	(1,000)	(3,000)	(4,000)	(3,000)
Net premiums	8,000	19,000	27,000	37,000
Policy charges and fee income:
Direct	102,000	398,000	495,000	439,000
Assumed	0			819,000
Ceded	(5,000)	(33,000)	(39,000)	(26,000)
Net policy charges and fee income	97,000	365,000	456,000	1,232,000
Asset management and service fees:
Direct	22,000	71,000	91,000	98,000
Assumed	0			165,000
Ceded	(2,000)	0	0	(8,000)
Net asset management and service fees	20,000	71,000	91,000	255,000
Realized investment gains (losses), net:
Direct	312,000			(4,689,000)
Assumed	0			12,351,000
Ceded	169,000			(173,000)
Total	481,000	(1,907,000)	(310,000)	7,489,000
Policyholders' benefits (including change in reserves):
Direct	31,000	247,000	343,000	49,000
Assumed	0			(253,000)
Ceded	(5,000)	(62,000)	(58,000)	(16,000)
Net policyholders benefits	26,000	185,000	285,000	(220,000)
Changes in fair value of insurance liabilities		1,195,000	(55,000)
Net policyholders benefits and changes in fair value of insurance liabilities	26,000	(1,010,000)	340,000	(220,000)
Interest credited to policyholders’ account balances:
Direct	91,000			175,000
Assumed	0			477,000
Ceded	(6,000)			(12,000)
Net interest credited to policyholders’ account balances	85,000	$ 0	$ 0	640,000
Reinsurance expense allowances and general and administrative expenses, net of capitalization and amortization	(41,000)			1,694,000
Unaffiliated
Policy charges and fee income:
Ceded	0			13,800
Interest credited to policyholders’ account balances:
Unaffiliated activity	$ 0			$ 400