Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional paid-in capital [Member]	Accumulated other comprehensive income (loss) [Member]	Retained earnings [Member]
Beginning Balance at Dec. 31, 2012	$ 199,780	$ 33	$ 184,431	$ 0	$ 15,316
Beginning Balance, shares at Dec. 31, 2012		33,451,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under equity compensation plans	8,385	$ 1	8,384
Issuance of common stock under equity compensation plans, shares		708,000
Excess tax benefit from share-based compensation	2,346		2,346
Stock-based compensation expense	8,017		8,017
Repurchases of common stock	(2,157)		(2,157)
Repurchases of common stock	(2,157)
Repurchase of common stock, shares		(86,000)
Changes in cumulative translation adjustment, net of tax	18			18
Net (loss) income	7,390				7,390
Ending Balance at Dec. 31, 2013	$ 223,779	$ 34	201,021	18	22,706
Ending Balance, shares at Dec. 31, 2013		34,073,000
Preferred stock, shares outstanding	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under equity compensation plans	$ 5,471	$ 0	5,471
Issuance of common stock under equity compensation plans, shares		428,000
Convertible senior notes, equity portion, net of tax and issuance costs	29,758		29,758
Tax impact from the issuance of convertible senior notes	(11,362)		(11,362)
Stock-based compensation expense	6,442		6,442
Repurchases of common stock	(1,956)		(1,956)
Repurchases of common stock	(1,956)
Repurchase of common stock, shares		(68,000)
Changes in cumulative translation adjustment, net of tax	(47)			(47)
Net (loss) income	(7,074)				(7,074)
Ending Balance at Dec. 31, 2014	$ 245,011	$ 34	229,374	(29)	15,632
Ending Balance, shares at Dec. 31, 2014		34,433,000
Preferred stock, shares outstanding	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under equity compensation plans	$ 3,318		3,318
Issuance of common stock under equity compensation plans, shares		308,000
Excess tax benefit from share-based compensation	571		571
Stock-based compensation expense	6,791		6,791
Repurchases of common stock	(30,400)	$ (1)	(30,933)
Repurchases of common stock	(30,934)
Repurchase of common stock, shares		(1,418,000)
Changes in cumulative translation adjustment, net of tax	(2)			(2)
Net (loss) income	(6,079)				(6,079)
Ending Balance at Dec. 31, 2015	$ 218,676	$ 33	$ 209,121	$ (31)	$ 9,553
Ending Balance, shares at Dec. 31, 2015		33,323,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	1,434,000