Other Income and Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other Income and Expenses [Abstract]
Interest income	$ (843)	$ (334)	$ (2,309)	$ (1,033)
Foreign currency (gain) loss, net	(454)	7,124	8,678	11,506
Loss on debt retirement	4,424	0	4,835	0
Other	227	(133)	(176)	(866)
Total other (income) expense, net	$ 3,354	$ 6,657	$ 11,028	$ 9,607