Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings (Deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning balance at Dec. 31, 2018	$ 1,214		$ 2,034	$ (678)	$ (143)
Beginning balance, shares at Dec. 31, 2018		1
Net income (loss)	18			18
Stock-based compensation	4		4
Exercise of stock options	1		1
Shares withheld for taxes	(2)		(2)
Other comprehensive income (loss)	10				10
Ending balance at Mar. 31, 2019	1,245		2,037	(660)	(133)
Ending balance, shares at Mar. 31, 2019		1
Beginning balance at Dec. 31, 2019	1,144		2,046	(775)	(128)
Beginning balance, shares at Dec. 31, 2019		1
Cumulative effect of accounting change at Dec. 31, 2019	(6)			(6)
Net income (loss)	(331)			(331)
Other comprehensive income (loss)	(39)				(39)
Ending balance at Mar. 31, 2020	$ 768		$ 2,046	$ (1,112)	$ (167)
Ending balance, shares at Mar. 31, 2020		1