Note 7 - Long-term Debt (Details Textual)			3 Months Ended		6 Months Ended
	Apr. 21, 2020 USD ($)	Nov. 30, 2017 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Long-term Debt, Total			$ 1,900,000		$ 1,900,000
Payments to Acquire Property, Plant, and Equipment, Total					118,471	$ 861,352
Proceeds from Issuance of Long-term Debt, Total					0	2,415,970
Gain (Loss) on Extinguishment of Debt, Total			$ 2,443,418	$ 0	$ 2,443,418	$ 0
HSBC Bank Mortgage Loan [Member]
Debt Instrument, Number of Payments					120
Debt Instrument, Periodic Payment, Total					$ 25,000
Long-term Debt, Total							$ 2,100,000
Debt Instrument, Interest Rate, Stated Percentage			1.82%		1.82%		1.89%
HSBC Bank Mortgage Loan [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate					1.75%
HSBC Bank Mortgage Loan [Member] | Prime Rate [Member]
Debt Instrument, Basis Spread on Variable Rate					0.50%
HSBC Bank Second Mortgage Loan [Member]
Debt Instrument, Number of Payments					60
Debt Instrument, Periodic Payment, Total					$ 62,481
Long-term Debt, Total			$ 9,100,000		$ 9,100,000		$ 9,300,000
Debt Instrument, Interest Rate, Stated Percentage			3.9148%		3.9148%
Debt Instrument, Face Amount		$ 10,387,500
HSBC Bank Second Mortgage Loan [Member] | Premises at 555 North Research Place, Central Islip, NY [Member]
Payments to Acquire Property, Plant, and Equipment, Total		$ 13,850,000
Paycheck Protection Program CARES Act [Member]
Proceeds from Issuance of Long-term Debt, Total	$ 2,415,970
Gain (Loss) on Extinguishment of Debt, Total			$ 2,443,418		$ 2,443,418