Condensed Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 566	$ 491
Other comprehensive income:
Change in gross unrealized investment gains/losses	196	(203)
Effect of income taxes	(45)	52
Total change in unrealized investment gains/losses, net of tax	151	(151)
Reclassification adjustment for net realized gains	0	(29)
Effect of income taxes	0	7
Total reclassification adjustment, net of tax	0	(22)
Other comprehensive income (loss), net of tax	151	(173)
Comprehensive loss attributable to equity method investment in Kindred at Home	(2)	0
Comprehensive income	$ 715	$ 318