Note 3 - Reverse Stock Split (Details Textual) $ / shares in Units, $ in Millions		3 Months Ended	12 Months Ended
	Oct. 19, 2020 $ / shares shares	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2022 $ / shares shares	Oct. 23, 2022 shares	Dec. 31, 2021 $ / shares shares	Oct. 18, 2020 shares
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares				$ 0.01		$ 0.01
Common Stock, Shares Authorized (in shares)				150,000,000	20,000,000	150,000,000
Common Stock, Shares, Outstanding, Ending Balance (in shares)				100,701,430		8,421,910
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio	20
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares	$ 0.01
Common Stock, Shares Authorized (in shares)	20,000,000						400,000,000
Common Stock, Shares, Outstanding, Ending Balance (in shares)	8,453,466						168,069,305
Adjustments to Additional Paid in Capital, Stock Split | $		$ 1.6	$ 1.6