Note 6 - Warrants (Details Textual)		3 Months Ended		9 Months Ended
	Jun. 01, 2021 USD ($) $ / shares shares	Sep. 30, 2021 USD ($) $ / shares shares	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) $ / shares shares	Sep. 30, 2020 USD ($)
Gain (Loss) on Derivative Instruments, Net, Pretax, Total | $		$ 200,273	$ 0	$ 1,312,899	$ 0
Public Warrants [Member]
Class of Warrant or Right, Outstanding (in shares)		6,325,000		6,325,000
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)		1		1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		$ 11.50		$ 11.50
Class of Warrant or Right, Redemption Price Per Share (in dollars per share) | $ / shares		0.01		0.01
Threshold Closing Price for Specified Number of Trading Days (in dollars per share) | $ / shares		$ 21.00		$ 21.00
Threshold Trading Days for Sale of Shares (Day)				20 days
Threshold Consecutive Trading Days for Sale of Shares (Day)				30 days
Warrants and Rights Outstanding | $		$ 1,279,182		$ 1,279,182
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		126,268		126,268
Private Warrants [Member]
Class of Warrant or Right, Outstanding (in shares)		556,313		556,313
Warrants and Rights Outstanding | $		$ 650,886		$ 650,886
Gain (Loss) on Derivative Instruments, Net, Pretax, Total | $		$ 200,273		$ 1,312,899
Private Warrants [Member] | Measurement Input, Risk Free Interest Rate [Member]
Derivative Liability, Measurement Input		0.0080		0.0080
Private Warrants [Member] | Measurement Input, Price Volatility [Member]
Derivative Liability, Measurement Input		0.691		0.691
Private Warrants [Member] | Measurement Input, Expected Term [Member]
Derivative Liability, Measurement Input		4.21		4.21
Private Warrants [Member] | Measurement Input, Exercise Price [Member]
Derivative Liability, Measurement Input		11.50		11.50
Private Warrants [Member] | Measurement Input, Share Price [Member]
Derivative Liability, Measurement Input		4.07		4.07
Pre-Funded Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)	1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares	$ 0.0001
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	5,066,600
Proceeds from Issuance of Warrants | $	$ 19,000,000.0
Investor Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)	0.75
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares	$ 4.125
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	6,900,000
Class of Warrant or Right, Exercised During Period (in shares)		0		23,849
Proceeds from Warrant Exercises | $		$ 0		$ 98,377