Investments (Contractual Maturity Dates For Fixed-Maturity And Short-Term Investments) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Amortized cost
Due in one year or less	$ 689
Due after one year through five years	3,675
Due after five years through ten years	3,404
Due after ten years	4,462
Total	12,230	$ 11,312
Fair value
Due in one year or less	697
Due after one year through five years	3,871
Due after five years through ten years	3,678
Due after ten years	4,776
Total	$ 13,022	$ 12,338
% of fair value
Due in one year or less	5.40%
Due after one year through five years	29.70%
Due after five years through ten years	28.20%
Due after ten years	36.70%
Total	100.00%