Note 7 - Taxes on Income - Deferred Income Tax Asset (Liability) (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Deferred income tax assets:
Pension accruals	$ 3,581,000	$ 3,678,000
Operating reserves and other accruals	3,656,000	1,231,000
Tax carrying value in excess of book basis of goodwill	1,377,000	1,514,000
Tax credits	99,000
Deferred income tax liabilities:
Book carrying value in excess of tax basis of property	(827,000)	(691,000)
Deferred expenses	(1,086,000)	(752,000)
Net deferred income tax asset	$ 6,800,000	$ 4,980,000