Note 6 - Shareholders' Equity (Details Textual) - Common Stock [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
	Apr. 07, 2022	Mar. 31, 2023
Stock Issued During Period, Shares, New Issues (in shares)		10
Registered Direct Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)	2,250
Shares Issued, Price Per Share (in dollars per share)	$ 25.90
Proceeds from Issuance of Common Stock	$ 58,275
Legal Fees	$ 55