Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional paid-in capital [Member]	Accumulated other comprehensive income (loss) [Member]	Retained earnings [Member]
Beginning Balance at Dec. 31, 2011	$ 185,386	$ 33	$ 175,030	$ 0	$ 10,323
Beginning Balance, shares at Dec. 31, 2011		33,276,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under equity compensation plans	5,581		5,581
Issuance of common stock under equity compensation plans, shares		415,000
Cancellation of common stock under equity compensation plans, shares		(9,000)
Income tax benefit due to exercise/disposition of employee stock options	1,102		1,102
Stock-based compensation expense	6,125		6,125
Repurchase of common stock	(3,407)		(3,407)
Repurchase of common stock, shares		(231,000)
Changes in cumulative translation adjustment, net of tax	0
Net (loss) income	4,993				4,993
Ending Balance at Dec. 31, 2012	199,780	33	184,431		15,316
Ending Balance, shares at Dec. 31, 2012		33,451,000
Preferred stock, shares outstanding	0
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
Income tax benefit due to exercise/disposition of employee stock options	2,346		2,346
Stock-based compensation expense	8,017		8,017
Repurchase of common stock	(2,157)		(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		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
Repurchase of common stock	(1,956)		(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