Note 8 - Leases - Maturities of Lease Liabilities (Details) - USD ($)	Jun. 30, 2019	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Remainder of: 2019, financing	$ 59,000
Remainder of: 2019, operating	526,000
Remainder of: 2019, total	585,000
2020, financing	117,000
2020, operating	862,000
2020, total	979,000
2021, financing	118,000
2021, operating	838,000
2021, total	956,000
2022, financing	112,000
2022, operating	827,000
2022, total	939,000
2023, financing	38,000
2023, operating	834,000
2023, total	872,000
Thereafter, financing
Thereafter, operating	9,923,000
Thereafter, total	9,923,000
Total undiscounted future minimum lease cash payments, financing	444,000
Total undiscounted future minimum lease cash payments, operating	13,810,000
Total undiscounted future minimum lease cash payments, total	14,254,000
Present value discount, financing	(18,000)
Present value discount, operating	(4,445,000)
Present value discount, total	(4,463,000)
Lease liability, financing	426,272	$ 453,485
Operating lease liability	9,364,989	$ 9,490,385	$ 10,100,000
Lease liability, total	$ 9,791,000