Note 6 - Stockholders' Equity (Details Textual)					9 Months Ended
	Oct. 04, 2022	Aug. 16, 2022 USD ($) shares	Aug. 12, 2022 USD ($) Days $ / shares shares	May 06, 2022 USD ($) $ / shares shares	Sep. 30, 2022 USD ($) $ / shares shares	Sep. 30, 2021 USD ($)	Oct. 06, 2022 shares	Dec. 31, 2021 $ / shares shares	Aug. 19, 2021 $ / shares
Common Stock, Shares Authorized (in shares)					300,000,000			300,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares					$ 0.01			$ 0.01
Warrants exercise price | $ / shares									$ 3.45
Proceeds from issuance of common stock and warrants | $					$ 14,401,000	$ 5,209,000
Payment of equity issuance costs | $					$ 333,000	$ 0
Common stock, shares outstanding (in shares)					77,080,169			14,239,177
Common stock, shares issued (in shares)					77,080,169			14,239,177
Maximum [Member]
Warrants exercise price | $ / shares					$ 694.80
Date of issuance of warrant					10 years
Minimum [Member]
Warrants exercise price | $ / shares					$ 0.25
Date of issuance of warrant					1 year
Subsequent Event [Member]
Common Stock, Shares Authorized (in shares)							280,000,000
Subsequent Event [Member] | Maximum [Member]
Reverse stock split ratio	50
Subsequent Event [Member] | Minimum [Member]
Reverse stock split ratio	10
May 2022 Registered Direct Offering
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares				$ 0.01
Offering shares (Per share)				3,646,690
Shares Issued, Price Per Share | $ / shares				$ 0.55
Warrants to purchase shares of common stock					3,646,690
Proceeds from issuance of common stock and warrants | $				$ 1,400,000
Aggregate Consideration | $				2,000,000.0
Payment of equity issuance costs | $				$ 600,000
Stock Issued During Period, Shares, New Issues				3,646,690
May 2022 Purchase Warrants
Warrants to purchase shares of common stock				3,646,690
Warrants exercise price | $ / shares				$ 0.7105
May 2022 Placement Agent Warrants
Warrants to purchase shares of common stock				218,801
Warrants exercise price | $ / shares				$ 0.7105
August 2022 Public Offering
Offering shares (Per share)		49,360,000
Warrants to purchase shares of common stock					110,400,000
Proceeds from issuance of common stock and warrants | $		$ 13,800,000
Payment of equity issuance costs | $		2,300,000
Net Proceeds | $		$ 11,500,000
Stock Issued During Period, Shares, New Issues		49,360,000
Consecutive trading day period | Days			30
Trading day conversion price period			300.00%
August 2022 Public Offering | Warrant One [Member]
Warrants to purchase shares of common stock		55,200,000
Warrants exercise price | $ / shares			$ 0.25
Date of issuance of warrant			1 year
August 2022 Public Offering | Warrant Two [Member]
Warrants to purchase shares of common stock		55,200,000
Warrants exercise price | $ / shares			$ 0.25
Date of issuance of warrant			5 years
Over Allotment Option [Member]
Offering shares (Per share)		7,200,000	7,200,000
Stock Issued During Period, Shares, New Issues		7,200,000	7,200,000
Over Allotment Option [Member] | Warrant One [Member]
Warrants to purchase shares of common stock		7,200,000	7,200,000
Over Allotment Option [Member] | Warrant Two [Member]
Warrants to purchase shares of common stock		7,200,000	7,200,000
Common Class A [Member] | August 2022 Public Offering
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares			$ 0.01
Offering shares (Per share)			42,160,000
Sale of public offering | $ / shares			$ 0.25
Stock Issued During Period, Shares, New Issues			42,160,000
Common Class B [Member] | August 2022 Public Offering
Public offering price			1,000
Offering shares (Per share)			1,460
Stock Issued During Period, Shares, New Issues			1,460
Common Class B [Member] | August 2022 Public Offering | Warrant one and Warrant two [Member]
Convertible Preferred Stock, Issuable Upon Conversion of All Shares (in shares)			4,000
Warrants exercise price | $ / shares			$ 0.25
Series B Convertible Preferred Stock [Member] | August 2022 Public Offering
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares			$ 0.01
Preferred stock, shares issued (in shares)		1,460	1,460
Convertible Preferred Stock, Issuable Upon Conversion of All Shares (in shares)			4,000
Weighted average daily dollar trading volume | $			$ 500,000
Series B Convertible Preferred Stock [Member] | August 2022 Public Offering | Warrant One [Member]
Convertible Preferred Stock, Issuable Upon Conversion of All Shares (in shares)			4,000
Series B Convertible Preferred Stock [Member] | August 2022 Public Offering | Warrant Two [Member]
Convertible Preferred Stock, Issuable Upon Conversion of All Shares (in shares)			4,000
Series C Preferred Stock [Member]
Preferred stock, shares issued (in shares)					317,420
Series C convertible preferred stock, shares outstanding (in shares)					11,674,131
Series A 4.5% Convertible Preferred Stock [Member]
Preferred Stock, Shares Authorized (in shares)					1,000,000			1,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares					$ 0.01			$ 0.01
Convertible Preferred Stock, Issuable Upon Conversion of All Shares (in shares)					6,479
Series A Preferred Stock [Member]
Preferred Stock, Shares Authorized (in shares)					7,000,000			7,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares					$ 0.01			$ 0.01
Preferred stock, shares issued (in shares)					200,000
Common stock, shares outstanding (in shares)					200,000			200,000
Common stock, shares issued (in shares)					200,000			200,000
LBS [Member]
Common Stock, Shares Authorized (in shares)					6,797,500
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares					$ 0.01
Preferred Stock, Shares Authorized (in shares)					33,594,625
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares					$ 0.001