Unaudited Consolidated Statement of Stockholders' Equity (USD $) In Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Other Comprehensive (Income) Loss	Accumulated Deficit
Beginning balance at Dec. 31, 2012	$ 154,730	$ 5	$ (3,701)	$ 195,485	$ (40)	$ (37,019)
Beginning balance, shares at Dec. 31, 2012		53,124	2,198
Net income	7,765					7,765
Foreign currency translation adjustment	(20)				(20)
Issuance costs of preferred stock and detachable warrants	(200)			(200)
Stock options exercised	2,364			2,364
Stock options exercised, shares		243
Stock surrendered for exercise of stock options	2,357		(2,357)
Stock surrendered for exercise of stock options, shares			161
Restricted stock granted, shares		278
Restricted stock forfeited, shares			12
Stock granted in incentive performance plan, shares		217
Treasury stock purchased	(2,658)		(2,658)
Treasury stock purchased, shares			180
Excess tax benefit related to share-based awards	602			602
Employee stock purchase plan	150			150
Employee stock purchase plan, shares			11
Stock compensation expense	2,241			2,241
Return of borrowed shares under share lending agreement			2,440
Ending balance at Mar. 31, 2013	$ 162,617	$ 5	$ (8,716)	$ 200,642	$ (60)	$ (29,254)
Ending balance, shares at Mar. 31, 2013		53,862	4,980