Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock	Treasury Stock	Additional Paid-in Capital Early Adoption of New Accounting Principle	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit) Early Adoption of New Accounting Principle	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income	Early Adoption of New Accounting Principle	Total
Balance at the beginning of the period at Dec. 31, 2013	$ 397			$ 721,352		$ 53,860	$ 4,621		$ 780,230
Balance (in shares) at Dec. 31, 2013	39,666
Increase (Decrease) in Stockholders' Equity
Net loss						(66,940)			(66,940)
Other comprehensive income (loss), net of tax							(3,152)		(3,152)
Share-based compensation expense				18,813					18,813
Net issuance under employee stock plans	$ 7			9,974					9,981
Net issuance under employee stock plans (in shares)	694
Balance at the end of the period at Dec. 31, 2014	$ 404			750,139		(13,080)	1,469		738,932
Balance (in shares) at Dec. 31, 2014	40,360
Increase (Decrease) in Stockholders' Equity
Net loss						(31,978)			(31,978)
Other comprehensive income (loss), net of tax							(121)		(121)
Share-based compensation expense				17,986					17,986
Net issuance under employee stock plans	$ 6			(988)					(982)
Net issuance under employee stock plans (in shares)	636
Purchases of common stock		$ (9,222)							(9,222)
Purchase of common stock (in shares)		469
Balance at the end of the period at Dec. 31, 2015	$ 410	$ (9,222)		767,137		(45,058)	1,348		714,615
Balance (in shares) at Dec. 31, 2015	40,996	469
Increase (Decrease) in Stockholders' Equity
Net loss						(122,210)			(122,210)
Other comprehensive income (loss), net of tax							429		429
Share-based compensation expense				15,741					15,741
Net issuance under employee stock plans	$ (3)	$ 19,948		(20,890)					(945)
Net issuance under employee stock plans (in shares)	(281)	(1,072)
Purchases of common stock		$ (13,035)							$ (13,035)
Purchase of common stock (in shares)		730							700
Balance at the end of the period (ASU 2016-09) at Dec. 31, 2016								$ 0
Balance at the end of the period at Dec. 31, 2016	$ 407	$ (2,309)		$ 763,303		$ (168,583)	$ 1,777		$ 594,595
Balance (in shares) at Dec. 31, 2016	40,715	127
Increase (Decrease) in Stockholders' Equity
Cumulative effect of change in accounting principle | ASU 2016-09			$ 1,315		$ (1,315)