Note 8 - Write-downs and Other Charges (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other Cost and Expense, Operating, Total	$ 55	$ 1,016
Gain (Loss) on Disposition of Assets, Total	$ (49)	(266)
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Asset		400
Development Agreements [Member]
Impairment of Intangible Assets, Finite-lived		$ 400