Note 15 - Supplemental Cash Flow Information - Supplemental Cash Flow Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income taxes paid	$ 5,076,000	$ 6,897,000	$ 5,274,000
Interest paid	$ 694,000	$ 523,000	$ 466,000