Note 7 - Leases (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Lessee, Operating Lease, Number of Right-of-Use Leases	4
Lessee, Operating Lease, Number of Right-of-Use Leases, Terminated	1
Lessee, Operating Lease, Number of Right-of-Use Leases, Subleased	1
Lessee, Operating Lease, Number Leases Exceeding One Year	3
Lessee, Operating Lease, Renewal Term (Year)	5 years
Operating Lease, Weighted Average Discount Rate, Percent	10.53%
Operating Lease, Weighted Average Remaining Lease Term (Year)	3 years 226 days
Lessee, Finance Lease, Number of Leases	0
Short-term Lease Commitment, Amount	$ 0
Operating Lease, Payments	$ 237,000	$ 247,000