Investments - Available-for-sale Fixed Maturity Securities by Contractual Maturity (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Cost or Amortized Cost
Cost or Amortized Cost	$ 45,010	$ 44,617
Estimated Fair Value
Estimated Fair Value	43,180	43,351
Available-for-sale Fixed Maturities
Cost or Amortized Cost
Due in one year or less	1,403	1,392
Due after one year through five years	11,744	11,318
Due after five years through ten years	13,199	13,440
Due after ten years	18,664	18,467
Cost or Amortized Cost	45,010	44,617
Estimated Fair Value
Due in one year or less	1,397	1,389
Due after one year through five years	11,529	11,214
Due after five years through ten years	12,789	13,187
Due after ten years	17,465	17,561
Estimated Fair Value	$ 43,180	$ 43,351