Note 8 - Leases - Lease Cost and Other Lease Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Operating lease cost	$ 360
Short-term lease cost	38
Variable lease cost	58
Sublease income	(8)
Total lease cost	448
Operating cash flows from operating leases	(429)
Right-of-use assets obtained in exchange for new operating lease obligations	$ 7,703
Weighted-average remaining lease term - operating leases (in years) (Year)	7 years 219 days
Weighted-average discount rate - operating leases	6.00%