CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Class A Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Retained Earnings New Accounting Pronouncement, Early Adoption, Effect	Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance, Shares		51,654,337
Beginning Balance at Dec. 31, 2014	$ 1,040	$ 1	$ 147	$ (634)	$ 1,535		$ (9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance, Shares		52,161,851
Issuance of treasury shares upon exercise of stock options, purchases under stock purchase plan and grants of restricted stock awards, shares		646,395
Issuance of treasury shares upon exercise of stock options, purchases under stock purchase plan and grants of restricted stock awards net of cancellations	17		1	16
Shares withheld related to net share settlement (in shares)		(138,881)
Shares withheld related to net share settlement (in shares)	(13)			(13)
Issuance of warrants exercisable for 250,000 shares, exercise price $89.34, expiration April 5, 2017	4		4
Additional tax benefit resulting from exercise of options	11		11
Share-based compensation	31		31
Net income (loss)	(158)				(158)
Unrealized loss on anticipated sales hedging transactions (net of income taxes)	(6)						(6)
Unrealized gain on forward interest rate swaps hedging transactions (net of income taxes)	(7)						(7)
Foreign currency translation adjustment	(26)						(26)
Ending Balance at Dec. 31, 2015	893	$ 1	194	(631)	1,377		(48)
Ending Balance, Shares at Dec. 31, 2015		52,161,851
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance, Shares		52,161,851
Beginning Balance, Shares		52,884,588
Issuance of treasury shares upon exercise of stock options, purchases under stock purchase plan and grants of restricted stock awards, shares		817,943
Issuance of treasury shares upon exercise of stock options, purchases under stock purchase plan and grants of restricted stock awards net of cancellations	11		(14)	25
Shares withheld related to net share settlement (in shares)		(95,206)
Shares withheld related to net share settlement (in shares)	(8)			(8)
Additional tax benefit resulting from exercise of options	3		3
Share-based compensation	27		27
Net income (loss)	(137)				(137)
Unrealized loss on anticipated sales hedging transactions (net of income taxes)	7						7
Unrealized gain on forward interest rate swaps hedging transactions (net of income taxes)	0						0
Foreign currency translation adjustment	(4)						(4)
Ending Balance at Dec. 31, 2016	792	$ 1	210	(614)	1,240		(45)
Ending Balance, Shares at Dec. 31, 2016		52,884,588
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance, Shares		52,884,588
Beginning Balance, Shares		53,236,095
Issuance of treasury shares upon exercise of stock options, purchases under stock purchase plan and grants of restricted stock awards, shares		410,239
Issuance of treasury shares upon exercise of stock options, purchases under stock purchase plan and grants of restricted stock awards net of cancellations	12		12	0
Shares withheld related to net share settlement (in shares)		(58,732)
Shares withheld related to net share settlement (in shares)	(6)			(6)
Share-based compensation	35		35
Net income (loss)	17				17
Unrealized loss on anticipated sales hedging transactions (net of income taxes)	(15)						(15)
Unrealized gain on forward interest rate swaps hedging transactions (net of income taxes)	6						6
Foreign currency translation adjustment	2						2
Ending Balance at Dec. 31, 2017	834	$ 1	$ 257	$ (620)	$ 1,248		$ (52)
Ending Balance, Shares at Dec. 31, 2017		53,236,095
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance, Shares		53,236,095
Cumulative effect of change in accounting principle	$ 9
Cumulative effect of change in accounting principle | ASU 2016-16						$ 9