Note 4 - Supplemental Cash Flow Information (Details Textual) - USD ($)	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Income Taxes Paid	$ 5,274,000	$ 3,284,000
Interest Paid	$ 357,000	$ 301,000
Company Stock Received in Lieu of Cash Stock Options Exercised	14,571	10,128
Stock Issued During Period, Shares, New Issues	50,224	20,408