Note 14 - Income Taxes - Reconciliation of the Federal Statutory Tax Rate to the Recorded Tax Provision (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Computed federal income taxes at the statutory rate (benefit)	$ (3,482)	$ (4,760)	$ (5,507)
Permanent tax differences	(23)	(122)	(262)
Foreign tax rates and tax credits differing from USA	435	747	1,021
Purchased goodwill and intangible impairments		828	1,072
Change in valuation allowance	114	1,965	1,425
Total income tax (benefit)	$ (2,956)	$ (1,342)	$ (2,251)
Effective tax rate	17.83%	5.92%	13.90%