INCOME TAXES Effective Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Income taxes at Netherlands rates (25%)	$ (18,871)	$ 39,515	$ 21,821
Jurisdictional differences in tax rates	10,018	(38,176)	(12,440)
Losses expired	(7,583)	(1,813)	(2,890)
Change in valuation allowance	(5,384)	(5,249)	2,496
Non-deductible expenses	(73)	288	(1,731)
Other	410	(901)	(6,103)
(Provision) / credit for income taxes	$ (21,483)	$ (6,336)	$ 1,153