Note 12 - Taxes on Income - Activity in the Valuation Allowance (Details) - SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Balance	$ 28,451	$ 29,782	$ 15,428
Additions	8,789	1,879	19,260
Reversals	(6,776)	(2,102)	(183)
Remeasurement of U.S. deferred tax balances	0	0	(5,141)
Other adjustments	3,783	(1,108)	418
Balance	$ 34,247	$ 28,451	$ 29,782