CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands	Total	Cashless	Restricted Stock Units (RSUs)	Common Stock	Common Stock Cashless	Common Stock Restricted Stock Units (RSUs)	Additional paid-in capital	Additional paid-in capital Cashless	Additional paid-in capital Restricted Stock Units (RSUs)	Accumulated deficit	Accumulated deficit Cashless	Accumulated deficit Restricted Stock Units (RSUs)	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Cashless	Accumulated Other Comprehensive Income (Loss) Restricted Stock Units (RSUs)
Beginning Balance at Dec. 31, 2010	$ 24,341			$ 439			$ 359,830			$ (335,928)			$ 0
Beginning Balance (in shares) at Dec. 31, 2010				43,894
Net loss	10,385			0			0			10,385			0
Other comprehensive income (loss)	0
Share-based compensation	2,458			0			2,458			0			0
Net distribution of common stock pursuant to restricted stock unit award plan (in shares)				828
Net distribution of common stock pursuant to restricted stock unit award plan	0			8			(8)			0			0
Common shares withheld for withholding taxes (in shares)					(228)	(288)
Common shares withheld for withholding taxes		(886)	(948)		(2)	(3)		(884)	(945)		0	0		0	0
Net issuance of common stock pursuant to cashless exercise of stock options (in shares)					611
Net issuance of common stock pursuant to cashless exercise of stock options		0			6			(6)			0			0
Issuance of common stock for exercise of stock options (in shares)				167
Issuance of common stock for exercise of stock options	217			2			215			0			0
Issuance of common stock for exercise of warrants	1,076			3			1,073			0			0
Issuance of common stock for exercise of warrants (in shares)				336
Ending Balance at Dec. 31, 2011	36,643			453			361,733			(325,543)			0
Ending Balance (in shares) at Dec. 31, 2011				45,320
Net loss	(9,668)			0			0			(9,668)			0
Other comprehensive income (loss)	(40)			0			0			0			(40)
Share-based compensation	1,733			0			1,733			0			0
Net distribution of common stock pursuant to restricted stock unit award plan (in shares)				827
Net distribution of common stock pursuant to restricted stock unit award plan	1			8			(7)			0			0
Common shares withheld for withholding taxes (in shares)					(5)	(296)
Common shares withheld for withholding taxes		(15)	(1,033)		0	(2)		(15)	(1,031)		0	0		0	0
Net issuance of common stock pursuant to cashless exercise of stock options (in shares)					14
Net issuance of common stock pursuant to cashless exercise of stock options		0			0			0			0			0
Issuance of common stock for exercise of stock options (in shares)				7
Issuance of common stock for exercise of stock options	9			0			9			0			0
Ending Balance at Dec. 31, 2012	27,630			459			362,422			(335,211)			(40)
Ending Balance (in shares) at Dec. 31, 2012				45,867
Net loss	(13,901)			0			0			(13,901)			0
Other comprehensive income (loss)	59			0			0			0			59
Share-based compensation	1,215			0			1,215			0			0
Warrants issued with promissory notes	400			0			400			0			0
Net distribution of common stock pursuant to restricted stock unit award plan (in shares)				826
Net distribution of common stock pursuant to restricted stock unit award plan	1			8			(7)			0			0
Common shares withheld for withholding taxes (in shares)					(1)	(321)
Common shares withheld for withholding taxes		(4)	(712)		0	(3)		(4)	(709)		0	0		0	0
Net issuance of common stock pursuant to cashless exercise of stock options (in shares)					7
Net issuance of common stock pursuant to cashless exercise of stock options		0			0			0			0			0
Issuance of common stock under “at the market” offerings, net of offering costs of $102 (in shares)				1,940
Issuance of common stock under “at the market” offerings, net of offering costs of $102	3,226			19			3,207			0			0
Issuance of common stock for exercise of stock options (in shares)				7
Issuance of common stock for exercise of stock options	9			0			9			0			0
Ending Balance at Dec. 31, 2013	$ 17,923			$ 483			$ 366,533			$ (349,112)			$ 19
Ending Balance (in shares) at Dec. 31, 2013				48,325