Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Accounting Policies [Abstract]
Net foreign exchange transaction gains (loss)	$ (1,131)	$ (216)
Accumulated income (loss) related to currency translation adjustments	(58,100)	(38,800)
Accumulated income (loss) related to derivative transactions	(6,200)	0
Accumulated income (loss) related to pension activity	$ 500	$ (500)