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Note 11 - Capital Stock (Details Textual)				3 Months Ended	4 Months Ended	6 Months Ended		8 Months Ended	18 Months Ended
	Apr. 06, 2021 USD ($) $ / shares shares	Jun. 02, 2020 USD ($) shares	May 28, 2020 $ / shares shares	Mar. 31, 2020 shares	Dec. 31, 2019 USD ($) shares	Jun. 30, 2021 USD ($) $ / shares shares	Jun. 30, 2020 USD ($)	Aug. 20, 2019 USD ($) shares	Aug. 20, 2019 USD ($) shares	Dec. 31, 2020 $ / shares shares	Aug. 13, 2019 USD ($)	Feb. 28, 2018 USD ($)
Proceeds from Issuance of Common Stock						$ 58,625,000	$ 59,549,751
Payments of Stock Issuance Costs						$ 3,357,544	$ 3,417,323
Class of Warrant or Right, Outstanding (in shares) | shares						105,556				105,556
Warrants for Common Class B Stock [Member]
Class of Warrant or Right, Outstanding (in shares) | shares						104,772
Warrants for Common Class A Stock [Member]
Class of Warrant or Right, Outstanding (in shares) | shares						784
Common Class A [Member]
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares						$ 0.001				$ 0.001
Common Stock, Voting Rights Per Share						1
Common Class A [Member] | Shelf Registration [Member]
Sale of Stock, Shelf Registration, Value, Available to Issue												$ 200,000,000
Sale of Stock, Shelf Registration, Value, Incremental Amount Available to Issue												$ 50,000,000
Stock Issued During Period, Shares, New Issues (in shares) | shares				0	448,880
Proceeds from Issuance of Common Stock					$ 9,450,789
Proceeds from Issuance of Common Stock, Net					9,122,227
Payments of Stock Issuance Costs					$ 328,562
Common Class A [Member] | Shelf Registration [Member] | Cowen and Company LLC [Member]
Sale of Stock, Shelf Registration, Value, Available to Issue											$ 75,000,000
Compensation, Percentage of Common Stock Sales											3.00%	3.00%
Stock Issued During Period, Shares, New Issues (in shares) | shares								942,223	2,141,452
Proceeds from Issuance of Common Stock								$ 22,753,943	$ 49,999,625
Proceeds from Issuance of Common Stock, Net								22,059,015
Payments of Stock Issuance Costs								$ 694,928
Common Class A [Member] | Underwriting Agreement [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares		3,680,000
Proceeds from Issuance of Common Stock		$ 58,900,000
Share Offering, Number of Shares Authorized (in shares) | shares			3,200,000
Share Price (in dollars per share) | $ / shares			$ 16.00
Stock Option, Exercisable, Remaining Contractual Term (Day)			30 days
Stock Option, Number of Securities Called by Each Stock Option (in shares) | shares			480,000
Common Class A [Member] | Underwriting Agreement [Member] | Adam Peterson and Alex Rozek, a Board Member, and Employee [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares			39,375
Common Class A [Member] | Public Offering Including Over-allotment Option [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares	2,645,000
Common Class A [Member] | Public Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares	2,345,000
Proceeds from Issuance of Common Stock	$ 58,625,000
Proceeds from Issuance of Common Stock, Net	55,400,625
Payments of Stock Issuance Costs	$ 133,169
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares	$ 1
Shares Issued, Price Per Share (in dollars per share) | $ / shares	$ 25.00
Common Class A [Member] | Over-Allotment Option [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares	345,000
Common Class A [Member] | Sold by Selling Stockholder [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares	300,000
Common Class A [Member] | Compensation for Offering [Member]
Stock Sale Agreement, Percent of Gross Proceeds	5.50%
Common Class B [Member]
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares						$ 0.001				$ 0.001
Common Stock, Voting Rights Per Share						10

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