Note 10 - Equity, Share-based Compensation, Warrants and Securities Offerings (Details Textual)		1 Months Ended				10 Months Ended	12 Months Ended
	Sep. 13, 2021 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares	Aug. 31, 2023	Jul. 31, 2023 $ / shares shares	Oct. 31, 2022 USD ($) $ / shares shares	Oct. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 $ / shares shares	Dec. 31, 2020	Dec. 31, 2019	Dec. 01, 2023 USD ($) $ / shares shares	Sep. 30, 2023 $ / shares	Sep. 30, 2022 $ / shares	Jul. 14, 2022 shares
Share Based Compensation, Maximum Percentage of Ownership				4.95%
Common Stock, No Par Value (in dollars per share) | $ / shares		$ 0					$ 0	$ 0
Common Stock, Capital Shares Reserved for Future Issuance (in shares)		1,230,000					1,230,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding, Number (in shares)		4,387,802					4,387,802	2,298,769	875,067
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)		114,056					114,056	55,424
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)							100,000	0
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period (in shares)							41,368	8,972
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price (in dollars per share) | $ / shares							$ 3.66
Share-based Compensation Arrangement By Share-based Payment Award Options Forfeitures and Expirations, Weighted Average Remaining Contractual Term (Year)							1 year
Restricted Stock Units (RSUs) [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested | $							$ 0.1
Restricted Stock Units (RSUs) [Member] | Share-Based Payment Arrangement, Tranche Two [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year)											5 years
RSUs and SUs [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested | $		$ 0.1					0.1
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding | $		0.1					0.1
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $		$ 0.1					$ 0.1
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)							1 year 3 months 18 days
Unvested RSU [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)		382,894					382,894
Stock Units [Member]
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $		$ 0.1					$ 0.1
Stock Issued During Period, Shares, Restricted Stock Award, Gross (in shares)								160,000
Stock Issued During Period, Shares, Restricted Stock Award, Cash Signing Fee | $								$ 0.2
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)							1 year 9 months 18 days
Options, RSUs and SUs [Member]
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $		$ 0.1					$ 0.1
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)							8 months 12 days
The 2014 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)		1,230,000					1,230,000								600,000
Common Stock, Capital Shares Reserved for Future Issuance (in shares)		0					0
The 2014 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year)							10 years
The 2014 Equity Incentive Plan [Member] | Stock Units [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding, Number (in shares)								1,000,000
Maximum [Member] | Share-Based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award Options Exercisable Period (Year)										4 years
Securities Purchase Agreement [Member]
Stock Issued During Period, Shares, New Issues (in shares)							2,222,222
Shares Issued, Price Per Share (in dollars per share) | $ / shares		$ 0.18					$ 0.18
Stock Issued During Period, Shares, New Issues (in shares)							2,222,222
Private Placement [Member]
Proceeds from Issuance or Sale of Equity | $		$ 4,000,000
Offering Pursuant to Shelf Registration Statement [Member]
Stock Issued During Period, Shares, New Issues (in shares)	230,750				675,000
Proceeds from Issuance or Sale of Equity | $	$ 2,800,000
Stock Issued During Period, Shares, New Issues (in shares)	230,750				675,000
Payments of Stock Issuance Costs | $	$ 200,000
Secured Promissory Note [Member] | Funicular Financing [Member]
Debt Instrument, Face Amount | $		$ 4,000,000					$ 4,000,000					$ 4
Debt Instrument, Discount Rate												10.00%
Debt Instrument, Interest Rate, Stated Percentage												13.50%
Debt Instrument, Fee Amount | $												$ 50,000
Preferred Share Purchase Right [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares				$ 6
The Warrant [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares	$ 1
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	230,769
Class of Warrant or Right, Change in Exercise Price, Maximum Percentage of Five-day Volume Weighted Average Common Stock	110.00%								110.00%
Warrants and Rights Outstanding | $	$ 600,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	230,769
Funicular Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		$ 0.18					$ 0.18
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		5,010,206					5,010,206
Warrants and Rights Outstanding, Term (Year)		5 years					5 years
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		5,010,206					5,010,206
The Prefunded Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares	$ 0.001				$ 0.0001
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	230,786				325,000
Class of Warrant or Right, Exercise Price, Prefunded (in dollars per share) | $ / shares	$ 6.499				$ 1.4999
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	230,786				325,000
Warrants Issued in Private Placement [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		$ 1.6			$ 1.875		$ 1.6
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					63,000
Proceeds from Issuance or Sale of Equity | $					$ 1,000,000
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs | $						$ 500,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					63,000
Warrants Issued in Private Placement [Member] | Maximum [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					2,000,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					2,000,000
Warrant A [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares	$ 10	$ 10					$ 10						$ 0.57	$ 2.72
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)												150,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)												150,000
Common Stock Purchase Warrant [Member] | Sabby [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)												323,810
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)												323,810
Common Stock Purchase Warrant [Member] | Hudson Bay Master Fund Ltd. [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)												155,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)												155,000
Sabby Warrant [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares												$ 0.2016
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)												1,200,000
Warrants and Rights Outstanding, Term (Year)		3 years					3 years
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)												1,200,000
Class of Warrant or Right, Date from which Warrants or Rights Exercisable		Dec. 01, 2023
Series A Through F Preferred Stock [Member]
Preferred Stock, Shares Outstanding, Ending Balance (in shares)									0
Series G Preferred Stock [Member]
Preferred Stock, Shares Outstanding, Ending Balance (in shares)		150					150	150	150
Convertible Preferred Stock, Shares Issued upon Conversion (in shares)		94.89915					94.89915
Preferred Stock, Liquidation Preference Per Share (in dollars per share) | $ / shares									$ 1,000
Series H Preferred Stock [Member]
Preferred Stock, No Par Value (in dollars per share) | $ / shares				0
Preferred Stock, Dividend Rate, Per-Dollar-Amount (in dollars per share) | $ / shares				$ 1
Series H Preferred Stock [Member] | Preferred Share Purchase Right [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)				0.001
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio			10