Note 7 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Net operating loss carryforward	$ 12,314	$ 9,495
Stock-based compensation	1,678	1,110
Accruals and reserves	427	192
Inventory	142	88
Lease liabilities	2,247	208
Tax credit carryforward	225	152
Other	48	4
Total deferred tax assets	17,081	11,249
Intangibles	(5,025)	(2,217)
Right-of-use assets	(2,261)	(218)
Fair value change in investments	(287)	0
Fixed assets	(959)	(108)
Other	(51)	0
Total deferred tax liabilities	(8,583)	(2,543)
Total deferred taxes	8,498	8,706
Less: valuation allowance	(8,498)	(8,706)
Net deferred taxes	$ 0	$ 0