Liability For Unpaid Claims (Changes In Liability For Unpaid Claims) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Liability For Unpaid Claims [Abstract]
Balance as of beginning-of-year	$ 5,934	$ 5,552
Reinsurance recoverable	151	152
Net balance as of beginning-of-year	5,783	5,400
Incurred related to:
Current year	1,025	885
Interest	42	43
All other incurred	(101)	(65)
Total incurred	966	863
Paid related to:
Current year	(302)	(240)
Prior years	(601)	(518)
Total paid	(903)	(758)
Net balance as of end-of-year	5,846	5,505
Reinsurance recoverable	151	150
Balance as of end-of-year	$ 5,997	$ 5,655