Note 1 - Basis of Presentation (Details Textual) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended		10 Months Ended
	Mar. 05, 2020	May 31, 2017	Mar. 31, 2020	Mar. 31, 2019	Sep. 30, 2019	Dec. 31, 2019	Nov. 30, 2018	Apr. 26, 2016
Net Income (Loss) Attributable to Parent, Total			$ (20,514)	$ (7,260)
Working Capital			6,700
Net Cash Provided by (Used in) Operating Activities, Total			(4,379)	(4,035)
Proceeds from Issuance of Common Stock			3,923	$ 7,891
Debt Instrument, Face Amount			27,300
Debt Conversion, Original Debt, Amount			38,900
Required Payment to Acquire Property Available for Purchase, Due End of Fiscal Year	$ 19,000
Percentage of Future Quarterly Interest Payments					25.00%
Interest Payments in Stock			$ 355
Stock Issued During Period, Shares, Conversion of Convertible Securities (in shares)			5,766,337
Preferred Stock, Shares Issued, Total (in shares)			10,000			0
Capital Expenditures Incurred but Not yet Paid			$ 516
Senior Secured Debt [Member]
Debt Instrument, Face Amount		$ 60,000
Debt Instrument, Additional Amount after Refinance		15,000
Prior Senior Secured Debt [Member]
Extinguishment of Debt, Amount		$ 45,000
2020 Convertible Senior Notes [Member]
Debt Instrument, Face Amount								$ 27,400
Debt Instrument, Interest Rate, Stated Percentage								7.00%
Debt Conversion, Original Debt, Amount	$ 27,300
Debt Conversion, Converted Instrument, Shares Issued (in shares)	10,000
Conversion of Convertible Senior Notes 2020 into Common Stock [Member]
Debt Conversion, Original Debt, Amount	$ 17,500
Debt Conversion, Converted Instrument, Amount	$ 2,600
At Market Issuance Sales Agreement [Member]
Proceeds from Issuance of Common Stock, Gross			$ 25,000		$ 12,400
At Market Issuance Sales Agreement, Maximum Aggregate Offering Price							$ 25,000
Stock Issued During Period, Shares, New Issues (in shares)			2,369,170
Proceeds from Issuance of Common Stock			$ 24,200