Note 9 - Common and Preferred Stock (Details Textual)						3 Months Ended						9 Months Ended		12 Months Ended	27 Months Ended
	Jul. 02, 2021 USD ($) $ / shares	Jul. 01, 2021 USD ($) $ / shares shares	Jun. 29, 2021 $ / shares shares	Mar. 05, 2020 shares	Jan. 31, 2013 shares	Sep. 30, 2023 $ / shares shares	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023 USD ($) $ / shares shares	Sep. 30, 2022 USD ($)	Dec. 31, 2022 $ / shares shares	Sep. 30, 2023 USD ($) $ / shares shares	Jul. 02, 2026 $ / shares
Common Stock, Shares Authorized (in shares)						85,000,000						85,000,000		70,000,000	85,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares						$ 0.01						$ 0.01		$ 0.01	$ 0.01
Common Stock, Shares, Issued (in shares)						66,604,981						66,604,981		55,823,810	66,604,981
Common Stock, Capital Shares Reserved for Future Issuance (in shares)					400,000
Percentage Of Projects Annual Capacity					51.00%
Number of Milestones for Common Stock Issuance					2
Shares Payable Term From Date Earned (Year)					3 years
Preferred Stock, Shares Issued, Total (in shares)						329						329		329	329
Preferred Stock, Dividend Rate, Percentage						8.875%	8.875%	8.875%	8.875%	8.875%	8.875%
Preferred Stock, Shares Authorized (in shares)						100,000						100,000		100,000	100,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares						$ 0.01						$ 0.01		$ 0.01	$ 0.01
Payments of Dividends | $												$ 3,841,000	$ 3,841,000		$ 10,396,000
Common Stock, Shares, Outstanding (in shares)						66,604,981						66,604,981		55,823,810	66,604,981
Preferred Stock, Shares Outstanding (in shares)						329						329		329	329
Preferred Class A [Member]
Convertible Preferred Stock, Shares Issued upon Conversion (in shares)				405.05
Series 1 Preferred Stock [Member]
Conversion of Stock, Shares Converted (in shares)														9,671
Conversion of Stock, Shares Issued (in shares)														3,917,235
Preferred Stock, Shares Issued, Total (in shares)														329
Depository Shares [Member]
Preferred Stock, Shares Per Depository Share (in dollars per share) | $ / shares			$ 0.001
Preferred Stock, Liquidation Preference Per Share (in dollars per share) | $ / shares	$ 25	$ 25
Preferred Stock, Liquidation Preference Per Share Per Year		2.21875
Dividends Payable, Amount Per Share (in dollars per share) | $ / shares						$ 0.55						$ 0.55			$ 0.55
Depository Shares [Member] | Sale Including Overallotment Option [Member]
Stock Issued During Period, Shares, New Issues (in shares)			2,000,000
Sale Including Overallotment Option [Member] | Sale Including Overallotment Option [Member] | Maximum [Member]
Stock Issued During Period, Shares, New Issues (in shares)			300,000
Series A Preferred Stock [Member]
Preferred Stock, Shares Issued, Total (in shares)						2,300						2,300		2,300	2,300
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
Preferred Stock, Shares Authorized (in shares)		7,500				7,500						7,500		7,500	7,500
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares		$ 0.01				$ 0.01						$ 0.01		$ 0.01	$ 0.01
Preferred Stock, Liquidation Preference, Value | $		$ 25,000
Preferred Stock, Liquidation Preference Per Share Per Year		2,218.75
Dividends Payable, Amount Per Share (in dollars per share) | $ / shares						$ 550						$ 550			$ 550
Conversion of Stock, Shares Cap (in shares)		3,748.13
Preferred Stock, Shares Outstanding (in shares)						2,300						2,300		2,300	2,300
Conversion of Convertible Senior Notes 2020 into Preferred Stock [Member]
Debt Conversion, Converted Instrument, Shares Issued (in shares)				10,000
Shares Earned Upon The Signing Of Binding Agreements [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)					100,000
Shares Earned Upon The Commencement Of Construction [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)					100,000
Forecast [Member] | Depository Shares [Member]
Preferred Stock, Redemption Price Per Share (in dollars per share) | $ / shares																$ 25
Forecast [Member] | Series A Preferred Stock [Member]
Preferred Stock, Redemption Price Per Share (in dollars per share) | $ / shares																$ 25,000
Upon Change of Control [Member] | Depository Shares [Member]
Preferred Stock, Redemption Price Per Share (in dollars per share) | $ / shares		$ 25
Upon Change of Control [Member] | Series A Preferred Stock [Member]
Preferred Stock, Redemption Price Per Share (in dollars per share) | $ / shares		$ 25,000