Note 5 - Leases - Leases Cost (Details) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
	Jan. 01, 2019	Sep. 30, 2020		Sep. 30, 2019		Sep. 30, 2020		Sep. 30, 2019		Dec. 31, 2019
Operating lease costs		$ 364		$ 377		$ 1,093		$ 1,013
Short-term and other lease costs		87		102		235		394
Total lease costs		451		479		1,328		1,407
Operating cash flows from operating leases		394		299		1,097		1,026
ROU assets obtained in exchange for new operating lease liabilities (1)	$ 2,200	$ 0	[1]	$ 869	[1]	$ 1,796	[1]	$ 3,450	[1]
Weighted-average remaining lease term (in years) (Year)		2 years 9 months 18 days				2 years 9 months 18 days				2 years 1 month 6 days
Weighted-average discount rate		2.90%				2.90%				3.70%

[1] For the nine months ended September 30, 2019, the amount includes $2.2 million for operating leases existing on January 1, 2019.