Note 7 - Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Gross trade receivables	$ 159,119	$ 299,962
Allowance for doubtful accounts	(7,189)	(5,458)
Net trade receivables	151,930	294,504
Income tax receivables	32,600	1,258
Other receivables	21,834	22,838
Total receivables, net	$ 206,364	$ 318,600