Income Taxes (Summary of Income / Asset Tax Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
U.S.	$ (10)	$ 22	$ 47
Non-U.S.	64,028	64,843	55,103
Current Income Tax	64,018	64,865	55,150
Deferred:
U.S.	(3,618)	1,827	1,337
Non-U.S.	(89,267)	(26,402)	(7,525)
Deferred Income Tax	(92,885)	(24,575)	(6,188)
Income tax expense	$ (28,867)	$ 40,290	$ 48,962