Note 1 - Basis of Presentation (Details Textual) - USD ($)						3 Months Ended		6 Months Ended	12 Months Ended
	Mar. 23, 2022	Jul. 02, 2021	Jul. 01, 2021	Jun. 29, 2021	Jun. 07, 2021	Mar. 31, 2022	Mar. 31, 2021	Jun. 30, 2021	Dec. 31, 2021
Net Income (Loss) Attributable to Parent, Total						$ (5,912,000)	$ (5,944,000)
Working Capital						17,000,000.0
Net Cash Provided by (Used in) Operating Activities, Total						(3,222,000)	(2,823,000)
Proceeds from Issuance of Common Stock						11,741,000	14,867,000
Payments to Acquire Property, Plant, and Equipment, Total						$ 530,000	513,000
Preferred Stock, Dividend Rate, Percentage						8.875%
Repayments of Long-term Debt, Total						$ 35,000	$ 13,000
Deposits, Segregated Account, Pre-fund Eight Quarterly Dividend Payments		$ 10,200,000
Interest Paid, Excluding Capitalized Interest, Operating Activities						875,000
Dividends Payable, Current						$ 1,265,000			$ 1,288,000
New Loan [Member]
Debt Instrument, Face Amount		50,000,000
Senior Secured Debt [Member]
Repayments of Long-term Debt, Total		$ 77,500,000
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		$ 54,000,000
Dividends Payable, Current						$ 1,270,000
Pipelines [Member]
Payments to Acquire Property, Plant, and Equipment, Total								$ 19,000,000
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					$ 15,000,000
Proceeds from Issuance of Common Stock, Net					$ 14,100,000
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	$ 12,000,000
Proceeds from Issuance of Common Stock, Net	$ 11,700,000