Investments - Schedule of Securities Pledged As Collateral For Repurchase Agreements (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 228,168	$ 199,895
Fair Value	218,644	184,167
Asset Pledged as Collateral \| Securities Sold under Agreements to Repurchase
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	6,528	6,841
Fair Value	6,225	5,878
U.S. government and agencies \| Asset Pledged as Collateral \| Securities Sold under Agreements to Repurchase
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,780	3,253
Fair Value	2,787	2,693
Foreign governments \| Asset Pledged as Collateral \| Securities Sold under Agreements to Repurchase
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	241	159
Fair Value	185	107
Corporate \| Asset Pledged as Collateral \| Securities Sold under Agreements to Repurchase
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,022	1,877
Fair Value	1,785	1,573
CLO \| Asset Pledged as Collateral \| Securities Sold under Agreements to Repurchase
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	611	587
Fair Value	608	588
ABS \| Asset Pledged as Collateral \| Securities Sold under Agreements to Repurchase
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	584	596
Fair Value	568	552
CMBS \| Asset Pledged as Collateral \| Securities Sold under Agreements to Repurchase
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	197	0
Fair Value	198	0
RMBS \| Asset Pledged as Collateral \| Securities Sold under Agreements to Repurchase
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	93	369
Fair Value	$ 94	$ 365