Note 6 - Leases - Maturities of Lease Liabilities (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Remainder of: 2020, financing	$ 143,000
Remainder of: 2020, operating	759,000
Remainder of: 2020, total	902,000
2021, financing	184,000
2021, operating	1,011,000
2021, total	1,195,000
2022, financing	111,000
2022, operating	1,014,000
2022, total	1,125,000
2023, financing	68,000
2023, operating	856,000
2023, total	924,000
2024, financing	40,000
2024, operating	752,000
2024, total	792,000
Thereafter, financing	1,000
Thereafter, operating	8,228,000
Thereafter, total	8,229,000
Total undiscounted future minimum lease cash payments, financing	547,000
Total undiscounted future minimum lease cash payments, operating	12,620,000
Total undiscounted future minimum lease cash payments, Total	13,167,000
Present value discount, financing	(8,000)
Present value discount, operating	(4,199,000)
Present value discount, Total	(4,207,000)
Lease liability, financing	538,825	$ 510,526
Operating lease liabilities	8,420,949	$ 8,560,892
Lease liability, Total	$ 8,960,000