Note 7 - Leases - Operating Lease Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating lease cost	$ 212	$ 222	$ 401	$ 445
Short-term lease cost	3	4	6	7
Variable lease cost	13	40	24	88
Sublease income	(55)	(55)	(109)	(109)
Total lease cost	$ 173	$ 211	$ 322	$ 431