Condensed Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 193	$ 650	$ 684	$ 1,765
Other comprehensive (loss) income:
Change in gross unrealized investment gains/losses	(9)	88	(212)	126
Effect of income taxes	2	(33)	54	(47)
Total change in unrealized investment gains/losses, net of tax	(7)	55	(158)	79
Reclassification adjustment for net realized gains	(23)	(2)	(52)	(28)
Effect of income taxes	8	0	15	10
Total reclassification adjustment, net of tax	(15)	(2)	(37)	(18)
Other comprehensive (loss) income, net of tax	(22)	53	(195)	61
Comprehensive income	$ 171	$ 703	$ 489	$ 1,826