Note 9 - Stockholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	9 Months Ended
	Aug. 04, 2022	Jun. 30, 2023	Sep. 30, 2023	Dec. 31, 2022	Aug. 03, 2022
Preferred Stock, Shares Authorized (in shares)			5,000,000	5,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share)			$ 0.0001	$ 0.0001
Preferred Stock, Shares Outstanding, Ending Balance (in shares)			0	0
Common Stock, Shares Authorized (in shares)			250,000,000	250,000,000	150,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share)			$ 0.0001	$ 0.0001
Common Stock, Increase in Shares Authorized (in shares)	100,000,000
Dividends, Total			$ 0
First Set of Warrants Expiring April 2024 [Member]
Warrant Exercise Price to be Entitled to Receive Cash Consideration, Fundamental Transaction (in dollars per share)			$ 1.1
Warrants Expiring March 2025 [Member]
Warrant Exercise Price to be Entitled to Receive Cash Consideration, Fundamental Transaction (in dollars per share)			2.5
Warrants Expiring February 2025 [Member]
Warrant Exercise Price to be Entitled to Receive Cash Consideration, Fundamental Transaction (in dollars per share)			$ 3.125
The 2023 Shelf Registration [Member]
Stock Issued During Period, Shares, New Issues (in shares)		16,000,000
Shares Issued, Price Per Share (in dollars per share)		$ 0.868
Proceeds from Issuance of Common Stock		$ 13,600
The 2023 Shelf Registration Option [Member]
Stock Issued During Period, Shares, New Issues (in shares)		2,400,000
Shares Issued, Price Per Share (in dollars per share)		$ 0.868