Note 13 - Equity Offerings (Details Textual) $ / shares in Units, $ in Thousands							12 Months Ended
	Oct. 25, 2024 USD ($) $ / shares shares	Oct. 24, 2024 $ / shares shares	Sep. 03, 2024 USD ($) $ / shares shares	Aug. 30, 2024 shares	Jan. 09, 2023 USD ($) $ / shares shares	Jan. 09, 2023 USD ($) $ / shares shares	Dec. 31, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares	Mar. 21, 2023 USD ($)	Jan. 08, 2023 $ / shares shares
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares
Payments of Costs Related to Exercise of Warrants | $							$ (0)	$ 181
Deemed Dividend on Warrant Inducement Offer | $	$ 5,200						$ 5,158	$ 800
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares							$ 0.0001	$ 0.0001
Accrued Liabilities, Current | $							$ 1,548	$ 1,733
Class of Warrant or Right, Exercised in Period (in shares)							6,209,979
Proceeds from Warrant Exercises | $							$ 1,185	1,326
Series A Convertible Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares					$ 0.0001	$ 0.0001
Abeyance Shares [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)	3,096,000
Private Placement [Member]
Proceeds from Issuance or Sale of Equity | $					$ 8,000
Payments of Stock Issuance Costs | $							(0)	640
Private Placement [Member] | Class A Units [Member]
Proceeds from Issuance or Sale of Equity | $					$ 900
Class of Unit, Price per Unit (in dollars per share) | $ / shares					$ 3	$ 3
Class of Unit, Percentage of Volume Weighted Average Price					90.00%
Units Issued, Shares Per Unit					0.1	0.1
Units Issued, Units issued During Period (in shares)						497,908
Private Placement [Member] | Class B Units [Member]
Proceeds from Issuance or Sale of Equity | $					$ 7,100
Class of Unit, Price per Unit (in dollars per share) | $ / shares					$ 1,000	$ 1,000
Units Issued, Shares Per Unit					0.1	0.1
Units Issued, Units issued During Period (in shares)					7,203
Units Issued, Convertible, Shares Issuable (in shares)					450,123	450,123
Private Placement [Member] | Series A Convertible Preferred Stock [Member]
Class of Unit, Price per Unit (in dollars per share) | $ / shares					$ 30	$ 30
Class of Unit, Percentage of Volume Weighted Average Price					90.00%
Preferred Stock, Convertible, Conversion Price (in dollars per share) | $ / shares					$ 1,000	$ 1,000
Maximum Beneficial Ownership					4.99%	4.99%
Maximum Beneficial Ownership, With Notice					9.99%	9.99%
The 2022 Offering [Member]
Accrued Liabilities, Current | $							$ 1,400
September 2024 Public Offering [Member]
Proceeds From Issuance or Sale of Equity, Net | $			$ 2,600
Stock Issued During Period, Shares, New Issues (in shares)			805,900
Proceeds from Issuance Initial Public Offering | $			$ 3,600
Payments of Stock Issuance Costs | $			$ 1,000
September 2024 Public Offering [Member] | Common Stock Units [Member]
Class of Unit, Price per Unit (in dollars per share) | $ / shares			$ 1
Units Issued, Shares Per Unit			1
Stock Issued During Period, Shares, New Issues (in shares)			805,900
September 2024 Public Offering [Member] | Pre-Funded Units [Member]
Class of Unit, Price per Unit (in dollars per share) | $ / shares			$ 0.9999
Over-Allotment Option [Member] | Underwriting Agreement [Member]
Stock Issued During Period, Shares, New Issues (in shares)				458,623
Option, Period (Year)			45 years
Option, Maximum Additional Shares (in shares)			468,041
Over-Allotment Option [Member] | Common Stock Units [Member] | Underwriting Agreement [Member]
Stock Issued During Period, Shares, New Issues (in shares)				458,623
Warrant Repricing 2023 [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares					$ 40	$ 40
Weighted Average [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares							$ 2.05
Existing Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)										33,161
Payments of Costs Related to Exercise of Warrants | $	$ 400
Deemed Dividend on Warrant Inducement Offer | $								$ 800
Stock Issued During Period, Shares, Warrant Exercises (in shares)	5,347,981	5,347,981
Class of Warrant or Right, Exercised During Period, Exercise Price (in dollars per share) | $ / shares	$ 0.7	$ 0.7
Proceeds from Warrant Exercises | $	$ 3,700
Existing Warrants [Member] | Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		1								$ 140
Existing Warrants [Member] | Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		$ 40								$ 5,265
Warrant Repricing 2023 [Member]
Proceeds from Issuance or Sale of Equity | $					$ 1,300
Payments of Costs Related to Exercise of Warrants | $					200
Proceeds From Issuance or Sale of Equity, Net | $					$ 1,100
Warrants and Rights Outstanding | $									$ 300
Series E Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares					$ 40	$ 40
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					33,161	33,161
Warrants and Rights Outstanding, Term (Year)					5 years	5 years
Warrants and Rights Outstanding | $					$ 1,900	$ 1,900			$ 1,900
Class of Warrant or Right, Exercised in Period (in shares)	33,160.8	33,160.8
Series F Warrants [Member]
Warrants and Rights Outstanding, Term (Year)					2 years	2 years
Class of Warrant or Right, Exercised in Period (in shares)	499,909.34	499,909.34
Series F Warrants [Member] | Class A Units [Member]
Units Issued, Warrants Per Unit					0.1	0.1
Series F Warrants [Member] | Class B Units [Member]
Units Issued, Warrants Per Unit					0.1	0.1
Series G Warrants [Member]
Warrants and Rights Outstanding, Term (Year)					6 years	6 years
Class of Warrant or Right, Exercised in Period (in shares)	499,909.34	499,909.34
Series G Warrants [Member] | Class A Units [Member]
Units Issued, Warrants Per Unit					0.1	0.1
Series G Warrants [Member] | Class B Units [Member]
Units Issued, Warrants Per Unit					0.1	0.1
Series F and Series G Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares					$ 30	$ 30
Warrants and Rights Outstanding | $					$ 5,500	$ 5,500
Maximum Beneficial Ownership					4.99%	4.99%
Maximum Beneficial Ownership, With Notice					9.99%	9.99%
September 2024 Pre-Funded Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			2,773,000
September 2024 Pre-Funded Warrants [Member] | Pre-Funded Units [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 0.0001
Units Issued, Warrants Per Unit			1
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)			1
Series H Warrants [Member]
Class of Warrant or Right, Exercised in Period (in shares)	1,990,000	1,990,000
Series H Warrants [Member] | Underwriting Agreement [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				458,623
Class of Warrant or Right, Maximum Additional for Option (in shares)			468,041
Series H Warrants [Member] | Common Stock Units [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 1
Warrants and Rights Outstanding, Term (Year)			6 months
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)			1
Series H Warrants [Member] | Pre-Funded Units [Member]
Units Issued, Warrants Per Unit			1
Series I Warrants [Member]
Class of Warrant or Right, Exercised in Period (in shares)	2,325,000	2,325,000
Series I Warrants [Member] | Underwriting Agreement [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				458,623
Class of Warrant or Right, Maximum Additional for Option (in shares)			468,041
Series I Warrants [Member] | Common Stock Units [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 1
Warrants and Rights Outstanding, Term (Year)			18 months
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)			1
Series I Warrants [Member] | Pre-Funded Units [Member]
Units Issued, Warrants Per Unit			1
Series J Warrants [Member] | Underwriting Agreement [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				458,623
Class of Warrant or Right, Maximum Additional for Option (in shares)			468,041
Series J Warrants [Member] | Common Stock Units [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 1
Warrants and Rights Outstanding, Term (Year)			5 years
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)			1
Series J Warrants [Member] | Pre-Funded Units [Member]
Units Issued, Warrants Per Unit			1
September 2024 Representative Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 1.55				1.55
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			214,734
Warrants and Rights Outstanding, Term (Year)			5 years
Maximum Beneficial Ownership			4.99%
Maximum Beneficial Ownership, With Notice			9.99%
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)			1
Class of Warrant or Right, Percentage of Outstanding Stock			6.00%
Class of Warrant or Right, Exercisable Period (Month)			6 months
Series Warrants [Member]
Maximum Beneficial Ownership			4.99%
Maximum Beneficial Ownership, With Notice			9.99%
Maximum Beneficial Ownership, Sixty One Days Notice			19.99%
Prefunded Warrants [Member]
Maximum Beneficial Ownership, With Notice			9.99%
Series K Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares	$ 0.7
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	10,695,962	10,695,962
Warrants and Rights Outstanding, Term (Year)	5 years 6 months
October 2024 Placement Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares	$ 1.085						$ 1.09
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	320,879
Class of Warrant or Right, Exercisable Period (Month)	6 months