FAIR VALUE OF ASSETS AND LIABILITIES - Fair Value Change In Insurance Contracts (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2023
Insurance liabilities
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total realized and unrealized gains (losses), Liabilities	$ (8,065)	$ (543)
Insurance liabilities | Retained Business
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total realized and unrealized gains (losses), Liabilities	(421)	(106)
Insurance liabilities | Ceded Business
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total realized and unrealized gains (losses), Liabilities	(7,644)	(437)
Reinsurance recoverables
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total realized and unrealized gains (losses), Assets	(15)	(29)
Reinsurance recoverables | Retained Business
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total realized and unrealized gains (losses), Assets	0	0
Reinsurance recoverables | Ceded Business
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total realized and unrealized gains (losses), Assets	(15)	(29)
Net modified coinsurance receivable
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total realized and unrealized gains (losses), Assets	(5,640)	(238)
Net modified coinsurance receivable | Retained Business
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total realized and unrealized gains (losses), Assets	0	0
Net modified coinsurance receivable | Ceded Business
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total realized and unrealized gains (losses), Assets	(5,640)	(238)
Deposit asset
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total realized and unrealized gains (losses), Assets	(1,989)	(169)
Deposit asset | Retained Business
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total realized and unrealized gains (losses), Assets	0	0
Deposit asset | Ceded Business
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total realized and unrealized gains (losses), Assets	$ (1,989)	$ (169)