Note 4 - Supplemental Cash Flow Information (Details Textual) - USD ($)	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Income Taxes Paid	$ 2,928,000	$ 2,172,000
Interest Paid	$ 228,000	$ 165,000
Company Stock Received in Lieu of Cash Stock Options Exercised	7,765	5,345
Stock Issued During Period, Shares, New Issues	27,432	10,204