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Investments - Investments - Available-for-Sale Securities (Details) - USD ($) $ in Millions	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Fixed maturities, available-for-sale, at fair value, amortized cost	$ 45,880		$ 44,538
Allowance for credit losses, fixed maturity, AFS	(14)	$ (14)	(16)	$ (19)	$ (18)	$ (21)
Gross Unrealized Gains, fixed maturities, available-for-sale	466		272
Gross Unrealized Losses, fixed maturities, available-for-sale	(1,774)		(2,227)
Fixed maturities, available-for-sale, at fair value (amortized cost of $54,478 and $53,805)	44,558		42,567
ABS
Debt Securities, Available-for-sale [Line Items]
Fixed maturities, available-for-sale, at fair value, amortized cost	4,355		3,948
Allowance for credit losses, fixed maturity, AFS	0		0
Gross Unrealized Gains, fixed maturities, available-for-sale	44		28
Gross Unrealized Losses, fixed maturities, available-for-sale	(23)		(39)
Fixed maturities, available-for-sale, at fair value (amortized cost of $54,478 and $53,805)	4,376		3,937
Collateralized Loan Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Fixed maturities, available-for-sale, at fair value, amortized cost	3,386		3,237
Allowance for credit losses, fixed maturity, AFS	0		0
Gross Unrealized Gains, fixed maturities, available-for-sale	8		13
Gross Unrealized Losses, fixed maturities, available-for-sale	(1)		0
Fixed maturities, available-for-sale, at fair value (amortized cost of $54,478 and $53,805)	3,393		3,250
CMBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturities, available-for-sale, at fair value, amortized cost	2,758		2,976
Allowance for credit losses, fixed maturity, AFS	(14)	$ (14)	(13)	(13)	(12)	(12)
Gross Unrealized Gains, fixed maturities, available-for-sale	24		21
Gross Unrealized Losses, fixed maturities, available-for-sale	(183)		(248)
Fixed maturities, available-for-sale, at fair value (amortized cost of $54,478 and $53,805)	2,585		2,736
Corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturities, available-for-sale, at fair value, amortized cost	22,962		21,555
Allowance for credit losses, fixed maturity, AFS	0		(3)	$ (6)	$ (6)	$ (9)
Gross Unrealized Gains, fixed maturities, available-for-sale	289		117
Gross Unrealized Losses, fixed maturities, available-for-sale	(726)		(1,033)
Fixed maturities, available-for-sale, at fair value (amortized cost of $54,478 and $53,805)	22,525		20,636
Foreign Govt./Govt. Agencies
Debt Securities, Available-for-sale [Line Items]
Fixed maturities, available-for-sale, at fair value, amortized cost	448		500
Allowance for credit losses, fixed maturity, AFS	0		0
Gross Unrealized Gains, fixed maturities, available-for-sale	12		3
Gross Unrealized Losses, fixed maturities, available-for-sale	(5)		(23)
Fixed maturities, available-for-sale, at fair value (amortized cost of $54,478 and $53,805)	455		480
Municipal
Debt Securities, Available-for-sale [Line Items]
Fixed maturities, available-for-sale, at fair value, amortized cost	4,985		5,574
Allowance for credit losses, fixed maturity, AFS	0		0
Gross Unrealized Gains, fixed maturities, available-for-sale	55		77
Gross Unrealized Losses, fixed maturities, available-for-sale	(390)		(347)
Fixed maturities, available-for-sale, at fair value (amortized cost of $54,478 and $53,805)	4,650		5,304
RMBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturities, available-for-sale, at fair value, amortized cost	5,793		5,610
Allowance for credit losses, fixed maturity, AFS	0		0
Gross Unrealized Gains, fixed maturities, available-for-sale	29		13
Gross Unrealized Losses, fixed maturities, available-for-sale	(309)		(393)
Fixed maturities, available-for-sale, at fair value (amortized cost of $54,478 and $53,805)	5,513		5,230
U.S. Treasuries
Debt Securities, Available-for-sale [Line Items]
Fixed maturities, available-for-sale, at fair value, amortized cost	1,193		1,138
Allowance for credit losses, fixed maturity, AFS	0		0
Gross Unrealized Gains, fixed maturities, available-for-sale	5		0
Gross Unrealized Losses, fixed maturities, available-for-sale	(137)		(144)
Fixed maturities, available-for-sale, at fair value (amortized cost of $54,478 and $53,805)	$ 1,061		$ 994