Condensed Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 644	$ 499	$ 1,328	$ 2,264
Other comprehensive (loss) income:
Change in gross unrealized investment gains/losses	(42)	26	(254)	152
Effect of income taxes	10	(9)	64	(56)
Total change in unrealized investment gains/losses, net of tax	(32)	17	(190)	96
Reclassification adjustment for net realized losses (gains)	3	0	(49)	(28)
Effect of income taxes	(1)	0	14	10
Total reclassification adjustment, net of tax	2	0	(35)	(18)
Other comprehensive (loss) income, net of tax	(30)	17	(225)	78
Comprehensive income	$ 614	$ 516	$ 1,103	$ 2,342