EQUITY - Cumulative Gains (Losses) (Details) - USD ($) $ in Millions	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	$ 2,605	$ 4,205	$ 3,423	$ 3,339	$ 3,715	$ 4,375
Total accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(7,451)		(8,754)
Unrealized gains (losses) on investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(6,501)		(7,334)
Market risk benefits - instrument-specific credit risk component
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(601)		(1,125)
Liability for future policy benefits - current discount rate component
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	255		372
Defined benefit pension plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(553)		(579)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(51)		(88)
Less: Accumulated other comprehensive income (loss) attributable to noncontrolling interest
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(19)		(42)
Accumulated other comprehensive income (loss) attributable to Holdings
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	$ (7,432)	$ (7,567)	$ (8,712)	$ (8,675)	$ (8,191)	$ (7,797)