Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock and Additional Paid - In Capital	Warrants	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Treasury Stock
Beginning balance at Dec. 31, 2009	$ 55,741	$ 172,679	$ 11	$ 66	$ (98,626)	$ (18,389)
Beginning balance, shares at Dec. 31, 2009		30,786,156				2,786,563
Net loss	(5,927)				(5,927)
Unrealized gain (loss) on available-for-sale securities, net of taxes	54			54
Repurchase of stock	(9)					(9)
Repurchase of stock, shares						1,646
Exercise of stock options	427	427
Exercise of stock options, shares	130,135	130,135
Release of restricted stock units and awards	469	469
Release of restricted stock units and awards, shares		100,521
Expiration of warrants	(11)		(11)
Stock based compensation	2,940	2,940
Ending balance at Dec. 31, 2010	53,684	176,515	0	120	(104,553)	(18,398)
Ending balance, shares at Dec. 31, 2010		31,016,812				2,788,209
Net loss	(1,604)				(1,604)
Unrealized gain (loss) on available-for-sale securities, net of taxes	(2)			(2)
Repurchase of stock	(6,450)					(6,450)
Repurchase of stock, shares						1,139,997
Issuance of stock for ESPP purchase	145	145
Issuance of stock for ESPP purchase, shares		28,702
Exercise of stock options	2,293	2,293
Exercise of stock options, shares	560,132	560,132
Release of restricted stock units and awards	1,323	1,323
Release of restricted stock units and awards, shares		180,384
Stock based compensation	2,232	2,232
Ending balance at Dec. 31, 2011	51,621	182,508	0	118	(106,157)	(24,848)
Ending balance, shares at Dec. 31, 2011		31,786,030				3,928,206
Net loss	(5,564)				(5,564)
Unrealized gain (loss) on available-for-sale securities, net of taxes	(9)			(9)
Repurchase of stock	(5,721)					(5,721)
Repurchase of stock, shares						1,054,538
Issuance of stock for ESPP purchase	122	122
Issuance of stock for ESPP purchase, shares		25,628
Exercise of stock options	1,046	1,046
Exercise of stock options, shares	231,403	231,403
Release of restricted stock units and awards	1,299	1,299
Release of restricted stock units and awards, shares		235,269
Stock based compensation	1,847	1,847
Ending balance at Dec. 31, 2012	$ 44,641	$ 186,822	$ 0	$ 109	$ (111,721)	$ (30,569)
Ending balance, shares at Dec. 31, 2012		32,278,330				4,982,744