Consolidated Statements Of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Consolidated Statements Of Comprehensive Income (Loss) [Abstract]
Net income (loss)	$ (87)	$ 20
Other comprehensive income (loss), net of tax	8	(1)
Comprehensive income (loss)	$ (79)	$ 19