Condensed Consolidated Statement of Stockholders' Equity - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]
Stockholders Equity, Beginning Balance at Dec. 31, 2017	$ 94,726	$ 52	$ 718,751	$ (624,077)
Stockholders Equity, Beginning Balance, Shares at Dec. 31, 2017		52,395,223
Issuance of common stock for exercise of stock options	101		101
Issuance of common stock for exercise of stock options, Shares		64,458
Stock-based compensation	1,499		1,499
Issuance of stock, value	45,996	$ 22	45,974
Issuance of stock, shares		21,850,000
Net loss	(11,525)			(11,525)
Stockholders Equity, Ending Balance at Mar. 31, 2018	$ 130,797	$ 74	$ 766,325	$ (635,602)
Stockholders Equity, Ending Balance, Shares at Mar. 31, 2018		74,309,681