Note 16 - Income Taxes - Summary of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating losses	$ 29,427	$ 26,790
Accruals	222	446
Deferred revenue		10
Stock options	1,191	1,425
Other deferred tax assets	765	716
Property and equipment	6	9
Lease liability	301
Total deferred tax assets	31,912	29,396
Lease asset	(301)
Total deferred tax liabilities	(301)
Valuation allowance	(31,611)	(29,396)
Net deferred taxes