Note 1 - Basis of Presentation (Details Textual) - USD ($) $ / shares in Units, $ in Thousands						3 Months Ended				6 Months Ended		12 Months Ended
	Mar. 23, 2022	Jul. 02, 2021	Jul. 01, 2021	Jun. 29, 2021	Jun. 07, 2021	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Net Income (Loss) Attributable to Parent, Total						$ (5,483)	$ (5,912)	$ (11,562)	$ (5,944)	$ (11,395)	$ (17,506)
Working Capital						$ 12,000				12,000
Net Cash Provided by (Used in) Operating Activities, Total										(7,550)	(5,999)
Proceeds from Issuance of Common Stock										11,741	30,354
Payments to Acquire Property, Plant, and Equipment, Total										1,748	20,177
Preferred Stock, Dividend Rate, Percentage						8.875%	8.875%
Repayments of Long-term Debt, Total										69	27
Deposits, Segregated Account, Pre-fund Eight Quarterly Dividend Payments		$ 10,200
Interest Paid, Excluding Capitalized Interest, Operating Activities										1,760
Dividends Payable, Current						$ 1,288				$ 1,288		$ 1,288
New Loan [Member]
Debt Instrument, Face Amount		50,000
Senior Secured Debt [Member]
Repayments of Long-term Debt, Total		$ 77,500
Depository Shares [Member]
Stock Issued During Period, Shares, New Issues (in shares)				2,000,000
Preferred Stock, Shares Per Depository Share (in dollars per share)				$ 0.001
Series A Preferred Stock [Member]
Preferred Stock, Dividend Rate, Percentage		8.875%	8.875%	8.875%						8.875%		8.875%
Proceeds From Issuance of Preferred Stock, Net of Issuance Costs		$ 54,000
Dividends Payable, Current						$ 1,290				$ 1,290
Pipelines [Member]
Payments to Acquire Property, Plant, and Equipment, Total											$ 19,000
Private Placement [Member] | Direct Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)					1,219,512
Shares Issued, Price Per Share (in dollars per share)					$ 12.30
Proceeds from Issuance of Common Stock					$ 15,000
Proceeds from Issuance of Common Stock, Net					$ 14,100
Over-Allotment Option [Member] | Depository Shares [Member] | Maximum [Member]
Stock Issued During Period, Shares, New Issues (in shares)				300,000
Direct Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)	6,857,140
Shares Issued, Price Per Share (in dollars per share)	$ 1.75
Proceeds from Issuance of Common Stock	$ 12,000
Proceeds from Issuance of Common Stock, Net	$ 11,700