Note 5 - Income Taxes - Major Components of Income Tax Provision (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Domestic	$ 22,171	$ (10,702)	$ 3,892
Foreign	(22,526)	(13,713)	(5,376)
Total current income tax provision	(355)	(24,415)	(1,484)
Deferred:
Domestic	(30,766)	7,480	(75,456)
Foreign	11,242	(10,493)	20,630
Total deferred income tax provision	(19,524)	(3,013)	(54,826)
Total income tax provision	$ (19,879)	$ (27,428)	$ (56,310)