Investments - Schedule of Amortized Cost and Fair Value of Fixed Maturity Securities, By Contractual Maturity (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Amortized Cost
Due in one year or less	$ 241
Due after one year through five years	4,271
Due after five years through ten years	10,502
Due after ten years	6,594
Mortgage-backed securities	5,281
Available-for-sale securities, Amortized Cost	26,889	$ 26,928
Estimated Fair Value
Due in one year or less	238
Due after one year through five years	4,305
Due after five years through ten years	10,697
Due after ten years	6,585
Mortgage-backed securities	5,180
Total fixed maturity securities	$ 27,005	$ 26,236