Note 7 - Taxes on Income (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	$ 28,000	$ 27,000	$ 28,000
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	28,000	44,000	$ 38,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	101,000	101,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	(58,000)
Undistributed Earnings of Foreign Subsidiaries	15,036,000	12,236,000
Other Noncurrent Liabilities [Member]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 500,000	$ 500,000