REVISION OF PREVIOUSLY ISSUED FINANCIAL STATEMENTS - Balance Sheets (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Funds withheld receivable	$ 9,755	$ 10,603	$ 10,677	$ 10,654
Reinsurance deposit assets	12,411	12,566	12,663	12,756
Current and deferred income taxes			127	149
Other assets	543	406			$ 132
Assets for Market Risk Benefits	34	24	22	24	15
Total Assets	47,712	44,196	39,963	37,730	10,163
Policyholders’ account balances	28,256	24,963		20,889
Liability for Market Risk Benefits	6,383	7,333	6,712	7,367	16
Future policy benefits and other policyholders' liabilities	1,801	1,653	1,450	1,298
Other liabilities	2,228	2,169	2,144	2,131
Total Liabilities	45,638	42,036	38,457	36,299	9,791
Retained earnings (accumulated deficit)	886	969	371	(109)	(160)
Accumulated other comprehensive income (loss)	(699)	(694)	(750)
Total Equity	2,074	2,160	1,506	1,431	372	$ 231
Total Liabilities and Equity	$ 47,712	$ 44,196	39,963	37,730	10,163
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Funds withheld receivable			10,550	10,615
Reinsurance deposit assets			12,682	12,782
Current and deferred income taxes			131	151
Other assets					131
Assets for Market Risk Benefits			24	26	17
Total Assets			39,861	37,721	10,164
Policyholders’ account balances				21,014
Liability for Market Risk Benefits			6,731	7,363	14
Future policy benefits and other policyholders' liabilities			1,352	1,209
Other liabilities			2,137	2,124
Total Liabilities			38,371	36,324	9,789
Retained earnings (accumulated deficit)			373	(143)	(157)
Accumulated other comprehensive income (loss)			(768)
Total Equity			1,490	1,397	375
Total Liabilities and Equity			39,861	37,721	10,164
Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Funds withheld receivable			127	39
Reinsurance deposit assets			(19)	(26)
Current and deferred income taxes			(4)	(2)
Other assets					1
Assets for Market Risk Benefits			(2)	(2)	(2)
Total Assets			102	9	(1)
Policyholders’ account balances				(125)
Liability for Market Risk Benefits			(19)	4	2
Future policy benefits and other policyholders' liabilities			98	89
Other liabilities			7	7
Total Liabilities			86	(25)	2
Retained earnings (accumulated deficit)			(2)	34	(3)
Accumulated other comprehensive income (loss)			18
Total Equity			16	34	(3)
Total Liabilities and Equity			$ 102	$ 9	$ (1)