EQUITY - Cumulative Gains (Losses) (Details) - USD ($) $ in Millions	Sep. 30, 2025	Jun. 30, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	$ 1,604	$ 2,605	$ 3,423	$ 4,956	$ 3,339	$ 4,375
Total accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(6,216)		(8,754)
Unrealized gains (losses) on investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(4,693)		(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	(1,122)		(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	195		372
Defined benefit pension plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(538)		(579)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(58)		(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	(25)		(42)
Accumulated other comprehensive income (loss) attributable to Holdings
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	$ (6,191)	$ (7,432)	$ (8,712)	$ (6,601)	$ (8,675)	$ (7,797)