Condensed Consolidated Statements of Changes in Stockholders' Equity (Deficit) (Unaudited) - 9 months ended Sep. 30, 2017 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2016		7,733
Beginning balance at Dec. 31, 2016	$ (7,516)	$ 8	$ 308,784	$ (316,308)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	903		903
Issuance of common stock due to the vesting of restricted stock, net of shares withheld to cover taxes (in shares)		129
Issuance of common stock and warrants, net of offering costs (in shares)		7,167
Issuance of common stock and warrants, net of offering costs	9,367	$ 7	9,360
Reclassification of warrant liabilities to equity	798		798
Net income	2,767			2,767
Ending balance (in shares) at Sep. 30, 2017		15,029
Ending balance at Sep. 30, 2017	$ 6,319	$ 15	$ 319,845	$ (313,541)