Medical Claims Payable ((Favorable) Unfavorable Developments By Changes In Key Assumptions) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Medical Claims Payable [Abstract]
Assumed trend factors	$ (1,429)	$ (599)	$ (325)
Assumed completion factors	(274)	(38)	(175)
Total	$ (1,703)	$ (637)	$ (500)