CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Treasury Stock [Member]
Balance at Dec. 31, 2008	$ 218,514	$ 388	$ 227,522	$ 16,215	$ 800	$ (26,411)
Balance (in shares) at Dec. 31, 2008		38,816,844				(3,097,364)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options	98		98
Exercise of common stock options (in shares)		17,925
Employee stock purchase plan	457	2	455
Employee stock purchase plan (in shares)		227,784
Stock-based compensation expense	5,015		5,015
Vesting of restricted stock units and restricted stock awards	(1,070)	3	(1,073)
Vesting of restricted stock units and restricted stock awards (in shares)		297,621
Tax deficiency from stock-based compensation	(1,386)		(1,386)
Retirement of treasury stock		(30)	(10,549)	(15,832)		26,411
Retirement of treasury stock (in shares)		(3,097,364)				3,097,364
Translation adjustments	326				326
Net income (loss)	4,707			4,707
Balance at Dec. 31, 2009	226,661	363	220,082	5,090	1,126
Balance (in shares) at Dec. 31, 2009		36,262,810
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options	333	1	332
Exercise of common stock options (in shares)		68,200
Stock repurchase and retirement of shares	(2,000)	(3)	(1,783)	(214)
Stock repurchase and retirement of shares (in shares)		(291,212)
Stock-based compensation expense	7,151		7,151
Vesting of restricted stock units and restricted stock awards	(1,305)	4	(1,309)
Vesting of restricted stock units and restricted stock awards (in shares)		359,013
Tax deficiency from stock-based compensation	(334)		(334)
Translation adjustments	(1,122)				(1,122)
Net income (loss)	(9,897)			(9,897)
Balance at Dec. 31, 2010	219,487		224,139	(5,021)	4
Balance (in shares) at Dec. 31, 2010	36,398,811	36,398,811
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options	1,724	2	1,722
Exercise of common stock options (in shares)		293,893
Employee stock purchase plan	977	2	975
Employee stock purchase plan (in shares)		187,036
Stock repurchase and retirement of shares	(2,230)	(3)	(1,985)	(242)
Stock repurchase and retirement of shares (in shares)		(323,361)
Stock-based compensation expense	5,868		5,868
Vesting of restricted stock units and restricted stock awards	(2,219)	4	(2,223)
Vesting of restricted stock units and restricted stock awards (in shares)		455,871
Tax deficiency from stock-based compensation	881		881
Changes in fair value of derivative, net of income tax	(380)				(380)
Translation adjustments	(1,662)				(1,662)
Net income (loss)	24,297			24,297
Balance at Dec. 31, 2011	$ 246,743		$ 229,377	$ 19,034	$ (2,038)
Balance (in shares) at Dec. 31, 2011	37,012,250	37,012,250