Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock and Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Treasury Stock
Beginning balance at Dec. 31, 2012	$ 29,278	$ 186,822	$ 109	$ (127,084)	$ (30,569)
Beginning balance, shares at Dec. 31, 2012		32,278,330			4,982,744
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	40,155			40,155
Unrealized gain (loss) on available-for-sale securities, net of taxes	$ 3		3
Repurchase of stock, shares	0
Issuance of stock for ESPP purchase	$ 198	$ 198
Issuance of stock for ESPP purchase, shares		36,921
Exercise of stock options	6,393	$ 6,393
Exercise of stock options, shares		956,633
Release of restricted stock units and awards, including related stock compensation	3,482	$ 3,482
Release of restricted stock units and awards, shares		347,882
Stock based compensation for stock options	1,162	$ 1,162
Ending balance at Dec. 31, 2013	80,671	$ 198,057	112	(86,929)	$ (30,569)
Ending balance, shares at Dec. 31, 2013		33,619,766			4,982,744
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,123			4,123
Unrealized gain (loss) on available-for-sale securities, net of taxes	(10)		(10)
Repurchase of stock	$ (15,000)				$ (15,000)
Repurchase of stock, shares	1,527,647				1,527,647
Issuance of stock for ESPP purchase	$ 381	$ 381
Issuance of stock for ESPP purchase, shares		38,298
Exercise of stock options	1,304	$ 1,304
Exercise of stock options, shares		205,744
Release of restricted stock units and awards, including related stock compensation	3,976	$ 3,976
Release of restricted stock units and awards, shares		361,970
Tax benefit/(deficiency) from the stock incentive plans	(161)	$ (161)
Stock based compensation for stock options	1,319	1,319
Ending balance at Dec. 31, 2014	76,603	$ 204,876	102	(82,806)	$ (45,569)
Ending balance, shares at Dec. 31, 2014		34,225,778			6,510,391
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,858			2,858
Unrealized gain (loss) on available-for-sale securities, net of taxes	(16)		(16)
Repurchase of stock	0				$ 0
Repurchase of stock, shares					0
Issuance of stock for ESPP purchase	367	$ 367
Issuance of stock for ESPP purchase, shares		45,820
Exercise of stock options	1,561	$ 1,630			$ (69)
Exercise of stock options, shares		239,071			5,503
Release of restricted stock units and awards, including related stock compensation	3,059	$ 3,059
Release of restricted stock units and awards, shares		334,641
Tax benefit/(deficiency) from the stock incentive plans	(228)	$ (228)
Stock based compensation for stock options	2,411	2,411
Ending balance at Dec. 31, 2015	$ 86,615	$ 212,115	$ 86	$ (79,948)	$ (45,638)
Ending balance, shares at Dec. 31, 2015		34,845,310			6,515,894