Note 7 - Stockholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		100 Months Ended
	Aug. 31, 2020	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Dec. 31, 2024	Nov. 30, 2016
Dividends, Preferred Stock		$ 1,204	$ 1,136
Preferred Stock, Shares Outstanding (in shares)		62,000		62,000	62,000
Convertible Preferred Stock, Shares Reserved for Future Issuance (in shares)		8,600,000		8,600,000
Series A Redeemable Convertible Preferred Stock [Member]
Temporary Equity, Shares Issued (in shares)		62,000		62,000	62,000
Deferred Offering Costs		$ 2,100		$ 2,100
Dividends, Preferred Stock		$ 1,200	1,100
Preferred Stock, Shares Outstanding (in shares)		62,000		62,000
Series A Redeemable Convertible Preferred Stock [Member] | Private Placement [Member]
Temporary Equity, Shares Issued (in shares)	85,000
Shares Issued, Price Per Share (in dollars per share)	$ 1,000
Proceeds from Issuance of Preferred Stock and Preference Stock	$ 85,000
Preferred Stock, Dividend Rate, Percentage	6.00%
Convertible Preferred Stock, Conversion Price (in dollars per share)	$ 9.5
Common Stock [Member]
Dividends, Preferred Stock			$ (0)
Stock and Warrant Repurchase Plan [Member]
Share Repurchase Program, Authorized, Amount						$ 35,000
Warrants Repurchased During Period (in shares)				6,011,926
Warrants Repurchased During Period, Value				$ 14,700
Share Repurchase Program, Remaining Authorized, Amount		$ 12,000		$ 12,000
Stock and Warrant Repurchase Plan [Member] | Common Stock [Member]
Stock Repurchased During Period, Shares (in shares)				875,218
Stock Repurchased During Period, Value				$ 8,300