Note 11 - Income Taxes - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carry forward	$ 4,596	$ 2,720
Research and development and other credit carry forward	18,944	17,750
Foreign tax credit carry forward	6,443	3,994
Accruals deductible in different periods	1,968	2,198
Leases	1,850
Intangible assets	741	1,081
Stock-based compensation	1,271	1,109
Total deferred tax assets	35,813	28,852
Less: valuation allowance	(10,486)	(9,808)
Deferred tax assets, net of valuation allowance	25,327	19,044
Deferred tax liabilities
Property and equipment, net	(611)	(710)
Operating lease right-of-use assets	(1,850)
Deferred tax liabilities	(2,461)	(710)
Net deferred tax assets	$ 22,866	$ 18,334