Note 6 - Leases - Lease Expense (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Amortization of right-of-use assets	$ 200,994	$ 142,582
Interest on lease liabilities	6,648	7,736
Operating lease cost	1,080,057	1,081,620
Sublease income	(39,900)	(47,200)
Total lease costs	$ 1,247,799	$ 1,184,738
Weighted-average remaining lease term - financing leases (in years) (Year)	3 years 2 months 12 days	3 years 4 months 24 days
Weighted-average remaining lease term - operating leases (in years) (Year)	13 years 7 months 6 days	14 years 4 months 24 days
Weighted-average discount rate - financing leases	1.06%	1.32%
Weighted-average discount rate - operating leases	5.75%	5.68%