Note 12 - Related Party Transactions (Details Textual) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended		12 Months Ended
	Sep. 20, 2022	Jun. 30, 2021	Jul. 31, 2021	Jun. 30, 2021	May 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	May 13, 2021	May 11, 2021
Common Stock, Par or Stated Value Per Share (in dollars per share)						$ 0.001	$ 0.001
Proceeds from Issuance of Common Stock						$ 14,864	$ 56,697	$ 29,434
Board of Directors Chairman [Member] | Letter Agreement [Member]
Related Party Transaction, Amounts of Transaction						$ 600
Board of Directors Chairman [Member] | Conversion of Loan Agreement into Common Stock [Member]
Debt Conversion, Original Debt, Amount				$ 41,000
Board of Directors Chairman [Member] | Private Placement [Member]
Stock Issued During Period, Shares, New Issues (in shares)		3,048,780
Common Stock, Par or Stated Value Per Share (in dollars per share)		$ 0.001		$ 0.001
Shares Issued, Price Per Share (in dollars per share)		$ 16.40		$ 16.40
Stock Issued During Period, Value, New Issues		$ 50,000
Proceeds from Issuance of Common Stock		8,400	$ 8,400
Board of Directors Chairman [Member] | Private Placement [Member] | Conversion of Loan Agreement into Common Stock [Member]
Debt Conversion, Original Debt, Amount		41,000
Board of Directors Chairman [Member] | Loan Agreement [Member]
Debt Instrument, Face Amount									$ 41,000	$ 41,000
Long-Term Debt, Total		$ 0		$ 0
Robert W. Duggan [Member] | Letter Agreement [Member]
Directors and Officers Liability Insurance, Period (Year)						1 year
Due to Related Parties, Total						$ 1,000
Related Party Transaction, Amounts of Transaction	$ 65,000
Robert W. Duggan [Member] | Letter Agreement [Member] | Subsequent Event [Member]
Directors and Officers Liability Insurance, Period (Year)					1 year