EQUITY - Cumulative Gains (Losses) (Details) - USD ($) $ in Millions	Jun. 30, 2026	Mar. 31, 2026	Dec. 31, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	$ 858	$ 1,860	$ 1,466	$ 2,605	$ 4,205	$ 3,423
Total accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(6,492)		(6,305)
Unrealized gains (losses) on investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(5,472)		(4,722)
Market risk benefits - instrument-specific credit risk component
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(722)		(1,166)
Liability for future policy benefits - current discount rate component
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	279		204
Defined benefit pension plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(514)		(563)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	(63)		(58)
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	(27)		(25)
Accumulated other comprehensive income (loss) attributable to Holdings
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) attributable to Holdings	$ (6,465)	$ (6,300)	$ (6,280)	$ (7,432)	$ (7,567)	$ (8,712)