Note 2 - Summary of Significant Accounting Policies - Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Finished goods	$ 10,143		$ 10,792
Raw materials	4,200		3,287
Work-in-process	1,194		759
Inventory reserves	(2,495)		(946)
Total inventories	$ 13,042	$ 12,828	$ 13,892