Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Series A Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]
Stockholders Equity, Beginning Balance at Dec. 31, 2019	$ 86,345	$ 1	$ 74	$ 851,957	$ (765,687)
Stockholders Equity, Beginning Balance, Shares at Dec. 31, 2019		103,000	1,867,176
Conversion of Series A convertible voting preferred stock to common stock		$ (1)	$ 8	(7)
Conversion of Series A convertible voting preferred stock to common stock, Shares		(103,000)	7,803,273
Reclassification of warrant liabilities to equity	62,175			62,175
Issuance of common stock in connection with an amendment to the asset purchase agreement	8,782		$ 1	8,781
Number of shares issued in connection with an amendment to asset purchase agreement			725,283
Issuance of warrant in connection with anamendment to the asset purchase agreement	3,188			3,188
Stock-based compensation	918			918
Reverse stock split adjustment			$ (73)	73
Net loss	(31,912)				(31,912)
Stockholders Equity, Ending Balance at Mar. 31, 2020	129,496		$ 10	927,085	(797,599)
Stockholders Equity, Ending Balance, Shares at Mar. 31, 2020			10,395,732
Stockholders Equity, Beginning Balance at Dec. 31, 2020	97,959		$ 11	944,537	(846,589)
Stockholders Equity, Beginning Balance, Shares at Dec. 31, 2020			11,128,484
Issuance of common stock	19,632		$ 1	19,631
Issuance of common stock, Shares			1,149,820
Issuance of common stock for exercise of common stock warrants	660			660
Issuance of common stock for exercise of common stock warrant, Shares			49,995
Issuance of common stock for exercise of common stock options	288			288
Issuance of common stock for exercise of stock options, Shares			21,662
Stock-based compensation	2,931			2,931
Net loss	(19,915)				(19,915)
Stockholders Equity, Ending Balance at Mar. 31, 2021	$ 101,555		$ 12	$ 968,047	$ (866,504)
Stockholders Equity, Ending Balance, Shares at Mar. 31, 2021			12,349,961