Consolidated Statements of Stockholders' Equity (Deficit) - 3 months ended Mar. 31, 2017 - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance at Dec. 31, 2016	$ (36,500)	$ 0	$ 2	$ 387,737	$ (424,239)
Beginning balance, shares at Dec. 31, 2016		0	1,590,948
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	1,356			1,356
Issuance of common stock as a result of public offering, net of fees	48,786		$ 5	48,781
Issuance of common stock as a result of public offering, net of fees, shares			5,250,000
Issuance of common stock for compensation	73			73
Issuance of common stock for compensation, shares			2,030
Issuance of preferred stock upon conversion of debt, shares		2,750,000
Issuance of preferred stock upon conversion of debt	27,398	$ 3		27,395
Net loss	(11,806)				(11,806)
Ending balances at Mar. 31, 2017	$ 29,307	$ 3	$ 7	$ 465,723	$ (436,426)
Ending balances, shares at Mar. 31, 2017		2,750,000	6,842,978