Note 10 - Equity Method Investment - TEL's Summarized Financial Information - Income Statement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue	$ 84,865	$ 94,432	$ 104,838
Operating Expenses	72,868	83,475	91,644
Operating Income	11,997	10,957	13,194
Net Income	$ 6,954	$ 6,598	$ 9,061