Segment Information (Reconciliation Of Reportable Segments Operating Revenues To Total Revenues Reported In The Consolidated Statements Of Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting [Abstract]
Reportable segments operating revenues	$ 30,649	$ 26,444	$ 89,275	$ 76,009
Net investment income	280	242	591	737
Net realized gains (losses) on financial instruments	247	1	241	90
Impairment recoveries (losses) recognized in income	(18)	(13)	(64)	(30)
Total revenues	$ 31,158	$ 26,674	$ 90,043	$ 76,806