Note 7 - Leases (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Lessee, Operating Lease, Number of Right-of-Use Leases	4		4
Lessee, Operating Lease, Number of Right-of-Use Leases, Terminated	1		1
Lessee, Operating Lease, Number of Right-of-Use Leases, Subleased	1		1
Lessee, Operating Lease, Number Leases Exceeding One Year	3		3
Lessee, Operating Lease, Renewal Term (Year)	5 years		5 years
Operating Lease, Weighted Average Discount Rate, Percent	10.53%		10.53%
Operating Lease, Weighted Average Remaining Lease Term (Year)	3 years 200 days		3 years 200 days
Lessee, Finance Lease, Number of Leases	0		0
Short-term Lease Commitment, Amount	$ 0		$ 0
Operating Lease, Payments	$ 237,000	$ 240,000	$ 474,000	$ 487,000