CONSOLIDATED STATEMENTS OF CHANGES IN CAPITAL DEFICIENCY (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Balance	$ (26,946)us-gaap_StockholdersEquity	$ (3,357)us-gaap_StockholdersEquity	$ (26,077)us-gaap_StockholdersEquity
Common stock issued for cash (net of issuance costs)			25,388
Share-based compensation related to stock options	467	1,013	4,612
Share-based compensation related to restricted stock award, net of forfeitures	775	3,076	3,139
Exercise of options granted to employees and non-employees (includes net exercise)	46	112	1,199
Net Loss	(29,943)us-gaap_NetIncomeLoss	(27,790)us-gaap_NetIncomeLoss	(11,618)us-gaap_NetIncomeLoss
Balance	(55,601)us-gaap_StockholdersEquity	(26,946)us-gaap_StockholdersEquity	(3,357)us-gaap_StockholdersEquity
Common Stock [Member]
Balance, shares	93,551,098	93,489,809	85,630,157
Balance	93	93	86
Common stock issued for cash (net of issuance costs) (in shares)			5,175,000
Common stock issued for cash (net of issuance costs)			5
Share-based compensation related to stock options
Share-based compensation related to restricted stock award, net of forfeitures			1
Share-based compensation related to restricted stock award, net of forfeitures (shares)	(81,209)	(17,834)	1,496,792
Exercise of options granted to employees and non-employees (includes net exercise)	1		1
Exercise of options granted to employees and non-employees (includes net exercise), shares	133,930	79,123	1,187,860
Net Loss
Balance	94	93	93
Balance, shares	93,603,819	93,551,098	93,489,809
Additional Paid-in Capital [Member]
Balance	184,346	180,145	145,814
Common stock issued for cash (net of issuance costs)			25,383
Share-based compensation related to stock options	467	1,013	4,612
Share-based compensation related to restricted stock award, net of forfeitures	775	3,076	3,138
Exercise of options granted to employees and non-employees (includes net exercise)	45	112	1,198
Net Loss
Balance	185,633	184,346	180,145
Accumulated Deficit [Member]
Balance	(211,385)	(183,595)	(171,977)
Common stock issued for cash (net of issuance costs)
Share-based compensation related to stock options
Share-based compensation related to restricted stock award, net of forfeitures
Exercise of options granted to employees and non-employees (includes net exercise)
Net Loss	(29,943)	(27,790)	(11,618)
Balance	$ (241,328)	$ (211,385)	$ (183,595)

Amount of recognized equity-based compensation during the period for restricted stock awards.

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