Note 7 - Taxes on Income - Deferred Income Tax Asset (Liability) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred income tax assets:
Pension accruals	$ 2,729	$ 2,606
Operating reserves and other accruals	1,984	2,174
Tax carrying value in excess of book basis of intangibles		866
Tax credits	748	255
Valuation allowance on tax credits	(748)	(255)
Deferred income tax liabilities:
Book carrying value in excess of tax basis of property	(1,495)	(937)
Book carrying value in excess of tax basis of intangibles	(6,906)
Tax effect of revenue recognition standard ASC 606	(2,657)
Deferred expenses	(2,130)	(1,809)
Net deferred income tax liability	$ (8,475)
Net deferred income tax asset		$ 2,900