Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings (Deficit) [Member]	Retained Earnings (Deficit) [Member] Cumulative Effect, Period of Adoption, Adjustment [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, 2018	1,214			2,034	(678)		(143)
Beginning balance, shares at Dec. 31, 2018			1
Net income (loss)	42
Ending balance at Sep. 30, 2019	1,267			2,045	(636)		(143)
Ending balance, shares at Sep. 30, 2019			1
Beginning balance at Mar. 31, 2019	1,245			2,037	(660)		(133)
Beginning balance, shares at Mar. 31, 2019			1
Net income (loss)	14				14
Stock-based compensation	4			4
Other comprehensive income (loss)	1						1
Ending balance at Jun. 30, 2019	1,264			2,041	(646)		(132)
Ending balance, shares at Jun. 30, 2019			1
Net income (loss)	10				10
Stock-based compensation	4			4
Other comprehensive income (loss)	(11)						(11)
Ending balance at Sep. 30, 2019	1,267			2,045	(636)		(143)
Ending balance, shares at Sep. 30, 2019			1
Beginning balance at Dec. 31, 2019	1,144	$ (6)		2,046	(775)	$ (6)	(128)
Beginning balance, shares at Dec. 31, 2019			1
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
Beginning balance at Dec. 31, 2019	1,144	$ (6)		2,046	(775)	$ (6)	(128)
Beginning balance, shares at Dec. 31, 2019			1
Net income (loss)	(383)
Other comprehensive income (loss)							(28)
Ending balance at Sep. 30, 2020	731			2,050	(1,164)		(156)
Ending balance, shares at Sep. 30, 2020			1
Beginning balance at Mar. 31, 2020	768			2,046	(1,112)		(167)
Beginning balance, shares at Mar. 31, 2020			1
Net income (loss)	(30)				(30)
Stock-based compensation	1			1
Other comprehensive income (loss)	8						8
Ending balance at Jun. 30, 2020	747			2,047	(1,142)		(159)
Ending balance, shares at Jun. 30, 2020			1
Net income (loss)	(22)				(22)
Stock-based compensation	3			3
Other comprehensive income (loss)	3						3
Ending balance at Sep. 30, 2020	$ 731			$ 2,050	$ (1,164)		$ (156)
Ending balance, shares at Sep. 30, 2020			1