Consolidated Statements of Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common stock	Additional paid-in capital	Accumulated other comprehensive income (loss)	Accumulated income (deficit)
Beginning balance at Dec. 31, 2008	$ 165,404	$ 31	$ 165,864	$ 69	$ (560)
Beginning balance, shares at Dec. 31, 2008		31,400
Issuance of common stock for acquisition, shares		700
Issuance of common stock for acquisition	6,881	1	6,880
Exercise of common stock options, shares		414
Exercise of common stock options	1,664		1,664
Non cash compensation recognized on stock options	5,266		5,266
Restricted stock grants, net of cancellations, shares		888
Restricted stock grants, net of cancellations	3,458	1	3,457
Cancellation of shares for payment of withholding tax, shares		(22)
Cancellation of shares for payment of withholding tax	(180)		(180)
Tax benefit related to the exercise of stock options	871		871
Tax benefit deficiencies related to restricted stock expense	(66)		(66)
Other comprehensive income/loss:
Unrealized loss on short-term investments	(71)			(71)
Net income (loss)	4,752				4,752
Total comprehensive income/loss	4,681
Ending balance at Dec. 31, 2009	187,979	33	183,756	(2)	4,192
Ending Balance, shares at Dec. 31, 2009		33,380
Exercise of common stock options, shares		760
Exercise of common stock options	7,255	1	7,254
Non cash compensation recognized on stock options and ESPP	4,559		4,559
Restricted stock grants, net of cancellations, shares		868
Restricted stock grants, net of cancellations	4,937	1	4,936
Cancellation of shares for payment of withholding tax, shares		(37)
Cancellation of shares for payment of withholding tax	(331)		(331)
Tax benefit related to the exercise of stock options	1,543		1,543
Tax benefit deficiencies related to restricted stock expense	(15)		(15)
Other comprehensive income/loss:
Unrealized loss on short-term investments	(8)			(8)
Net income (loss)	12,346				12,346
Total comprehensive income/loss	12,338
Ending balance at Dec. 31, 2010	218,265	35	201,702	(10)	16,538
Ending Balance, shares at Dec. 31, 2010		34,971
Exercise of common stock options, shares		7
Exercise of common stock options	12		12
Non cash compensation recognized on stock options and ESPP	973		973
Restricted stock grants, net of cancellations, shares		575
Restricted stock grants, net of cancellations	5,557	1	5,556
Cancellation of shares for payment of withholding tax, shares		(37)
Cancellation of shares for payment of withholding tax	(303)		(303)
Employee stock purchase plan, shares		96
Employee stock purchase plan	413		413
Tax benefit deficiencies related to restricted stock expense	(426)		(426)
Other comprehensive income/loss:
Unrealized loss on short-term investments	(25)			(25)
Net income (loss)	(159,606)				(159,606)
Total comprehensive income/loss	(159,631)
Ending balance at Dec. 31, 2011	$ 64,860	$ 36	$ 207,927	$ (35)	$ (143,068)
Ending Balance, shares at Dec. 31, 2011		35,612