Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common stock [Member]	Treasury stock [Member]	Additional paid-in capital [Member]	Accumulated Deficit [Member]	Accumulated other comprehensive income [Member]
Beginning balance at Dec. 31, 2012	$ 129,858	$ 7	$ (3,352)	$ 285,332	$ (152,160)	$ 31
Beginning balance, shares at Dec. 31, 2012		65,399
Issuance of common stock for employee stock options exercised and vesting of restricted shares	5,873			5,873
Issuance of common stock for employee stock options exercised and vesting of restricted shares, shares		3,783
Issuance of common stock for acquisitions	852			852
Issuance of common stock for acquisitions, shares		471
Stock-based compensation	34,777			34,777
Foreign currency translation, net of tax	290					290
Unrealized gain on marketable securities, net of tax	(45)					(45)
Net loss	(75,371)				(75,371)
Ending balance at Dec. 31, 2013	96,234	$ 7	(3,352)	326,834	(227,531)	276
Ending balance, shares at Dec. 31, 2013		69,653
Issuance of common stock for employee stock options exercised and vesting of restricted shares	2,492			2,492
Issuance of common stock for employee stock options exercised and vesting of restricted shares, shares		4,264
Stock-based compensation	34,261			34,261
Foreign currency translation, net of tax	(205)					(205)
Unrealized gain on marketable securities, net of tax	(32)					(32)
Net loss	(56,153)				(56,153)
Ending balance at Dec. 31, 2014	76,597	$ 7	(3,352)	363,587	(283,684)	39
Ending balance, shares at Dec. 31, 2014		73,917
Issuance of common stock for employee stock options exercised and vesting of restricted shares	287			287
Issuance of common stock for employee stock options exercised and vesting of restricted shares, shares		2,478
Stock-based compensation	20,290			20,290
Foreign currency translation, net of tax	(100)					(100)
Unrealized gain on marketable securities, net of tax	(80)					(80)
Net loss	(34,853)				(34,853)
Ending balance at Dec. 31, 2015	$ 62,141	$ 7	$ (3,352)	$ 384,164	$ (318,537)	$ (141)
Ending balance, shares at Dec. 31, 2015		76,395