Note 7 - Taxes on Income - Income Tax Provisions (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal	$ 5,642,000	$ 6,527,000	$ 5,576,000
State and local	628,000	519,000	603,000
	6,270,000	7,046,000	6,179,000
Deferred tax provision (benefit)	(1,010,000)	(1,216,000)	1,000
	$ 5,260,000	$ 5,830,000	$ 6,180,000