Note 4 - Supplemental Cash Flow Information (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Taxes Paid	$ 39,000	$ 29,000
Interest Paid	$ 129,000	$ 99,000
Company Stock Received in Lieu of Cash Stock Options Exercised	16,500	0
Stock Issued During Period, Shares, New Issues	41,544	0