Note 6 - Leases (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Lease, Cost, Total	$ 2,300	$ 2,500
Short-term Lease, Cost	200
Variable Lease, Cost	300
Operating Lease Liability, Renewal Period	1,000
Operating Lease, Liability, Current	$ 1,867
Operating Lease, Weighted Average Remaining Lease Term	7 years 73 days
Operating Lease, Weighted Average Discount Rate, Percent	5.25%
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 333