Investments (Contractual Maturity Dates For Fixed-Maturity And Short-Term Investments) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Amortized cost
Due in one year or less	$ 713
Due after one year through five years	3,966
Due after five years through ten years	3,533
Due after ten years	4,767
Total	12,979	$ 12,230
Fair value
Due in one year or less	709
Due after one year through five years	3,834
Due after five years through ten years	3,357
Due after ten years	4,232
Total	$ 12,132	$ 13,022
% of fair value
Due in one year or less	5.80%
Due after one year through five years	31.60%
Due after five years through ten years	27.70%
Due after ten years	34.90%
Total	100.00%