Note 12 - Commitments and Contingencies (Details Textual) - BND [Member] $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($)	Mar. 06, 2019 a
Area Available for Lease (Acre) | a		984
Lessee, Operating Lease, Liability, to be Paid Per Quarter | $	$ 1.5