Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Cumulative Translation Adjustment Summary [Roll Forward]
Beginning Balance			$ (136,020)	$ (36,087)
Other current period change	$ (32,264)	$ 27,027	(18,578)	(30,345)
Ending Balance	(154,598)	(66,432)	(154,598)	(66,432)
Accumulated Other Comprehensive Income Loss Actuarial Loss Net Of Tax [Roll Forward]
Beginning Balance			(576,993)	(585,941)
Amortization			9,754	9,790
Other current period change			(5,597)	(5,321)
Ending Balance	(572,836)	(581,472)	(572,836)	(581,472)
Accumulated Other Comprehensive Income Loss Prior Service Credit Net Of Tax [Roll Forward]
Beginning Balance			278	1,758
Amortization			(72)	(712)
Other current period change			(5,425)	0
Ending Balance	(5,219)	1,046	(5,219)	1,046
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance			(712,735)	(620,270)
Amortization			9,682	9,078
Other current period change			(29,600)	(35,666)
Ending Balance	$ (732,653)	$ (646,858)	$ (732,653)	$ (646,858)