Note 8 - Leases - Maturities of Lease Liabilities (Details) - USD ($)	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
2020, financing	$ 132,000
2020, operating	1,043,000
2020	1,175,000
2021, financing	132,000
2021, operating	1,020,000
2021	1,152,000
2022, financing	126,000
2022, operating	1,011,000
2022	1,137,000
2023, financing	53,000
2023, operating	1,014,000
2023	1,067,000
2024, financing	10,000
2024, operating	856,000
2024	866,000
Thereafter, financing
Thereafter, operating	8,980,000
Thereafter	8,980,000
Total undiscounted future minimum lease cash payments, financing	453,000
Total undiscounted future minimum lease cash payments, operating	13,924,000
Total undiscounted future minimum lease cash payments, operating	14,377,000
Present value discount, financing	(14,000)
Present value discount, operating	(4,818,000)
Present value discount	(4,832,000)
Lease liability, financing	438,580	$ 481,830
Lease liability, operating	9,105,503	$ 9,655,304
Lease liability	$ 9,545,000