Liability For Unpaid Claims (Changes In Liability For Unpaid Claims) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Liability For Unpaid Claims [Abstract]
Balance as of beginning-of-year	$ 5,552	$ 5,335
Reinsurance recoverable	152	143
Net balance as of beginning-of-year	5,400	5,192
Incurred related to:
Current year	885	803
Interest	43	41
All other incurred	(65)	(85)
Total incurred	863	759
Paid related to:
Current year	(240)	(215)
Prior years	(518)	(482)
Total paid	(758)	(697)
Net balance as of end-of-year	5,505	5,254
Reinsurance recoverable	150	143
Balance as of end-of-year	$ 5,655	$ 5,397