Note 5 - Balance Sheet Components - Right-of-Use Assets, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Right-of-use assets, net	$ 1,990
Facilities [Member]
Right-of-use assets, net	1,985
Office Equipment [Member]
Right-of-use assets, net	$ 5