Income Taxes (Current and Deferred Income Tax Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
U.S. federal	$ 470	$ 300	$ 59
Non-U.S.	7,625	9,142	10,180
U.S. state and local	201	162	157
Total current income tax provision (benefit)	8,296	9,604	10,396
Deferred:
U.S. federal	9,981	(44,068)	227
Non-U.S.	334	(3,078)	(2,066)
U.S. state and local	(900)	(674)	10
Total deferred income tax provision (benefit)	9,415	(47,820)	(1,829)
Total:
U.S. federal	10,451	(43,768)	286
Non-U.S.	7,959	6,064	8,114
U.S. state and local	(699)	(512)	167
Total income tax provision (benefit)	$ 17,711	$ (38,216)	$ 8,567