Note 7 - Supplemental Cash Flow Information - Cash Paid for Interest and Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest (net of amounts capitalized)	$ 18,927	$ 21,385	$ 14,444
Income taxes paid, net of refunds	$ 3,404	$ (5,169)	$ 43,237