Note 5 - Stockholders' Equity and Dilutive Equity Instruments (Details Textual) - USD ($) $ / shares in Units, $ in Millions		9 Months Ended
	Apr. 24, 2020	Sep. 30, 2020	Sep. 30, 2019	Apr. 13, 2020
Operating Loss Carryforwards, Total		$ 280
Percentage of Ownership of Outstanding Common Stock, Subject to Dilution				4.99%
Percentage of Additional Ownership Over 4.99% in Otustanding Common Stock, Subject to Dilution				0.50%
Number of Rights Issued Per Common Stock Owned (in shares)	1
Series A Junior Participating Preferred Stock [Member]
Number of Shares Per Right (in shares)	1.001
Preferred Stock, No Par Value (in dollars per share)	$ 0
Shares Issued, Price Per One One Thousandths of a Share (in dollars per share)	38.00
Redemption Price, Per Right (in dollars per share)	$ 0.001
Out-of-the-money Warrants [Member]
Class of Warrant or Right, Outstanding (in shares)		5,923,399	5,923,399
Series A Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 57.06	$ 57.06
Series B Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		62.28	62.28
GLF Equity Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 100.00	$ 100.00
In-the-money Warrants and Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)		2,488,752	3,397,110