Note 8 - Lease Revenue (Details Textual) - USD ($)		3 Months Ended		6 Months Ended
	Jan. 01, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Lessor, Operating Lease, Term of Contract (Year)	7 years
Lessor, Operating Lease, Renewal Term (Year)	5 years
Revenue from Contract with Customer, Excluding Assessed Tax, Total		$ 8,016,560	$ 8,257,013	$ 18,299,225	$ 17,746,517
CAM Lease Revenue Billed [Member]
Revenue from Contract with Customer, Excluding Assessed Tax, Total				$ 201,600	$ 159,800
Minimum [Member]
Operating Lease, Lease Income, Lease Payments	$ 193,000
Maximum [Member]
Operating Lease, Lease Income, Lease Payments	$ 410,000