Accumulated Other Comprehensive Income (Loss) - Classification and Amount of Reclassifications from Accumulated Other Comprehensive Income to Consolidated Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax effect of net (loss) gain	$ (6,909)	$ 17,668	$ (4,257)	$ 50,108
Net Loss	(240,931)	(56,075)	(552,184)	(169,306)
Loss Before Income Taxes	(234,022)	(73,743)	(547,927)	(219,414)
Reclassification Out of Accumulated Other Comprehensive Income (Loss) | Derivative Instruments | (Loss) gain on foreign currency forward exchange contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of sales	(4,767)	259	(9,150)	2,466
Tax effect of net (loss) gain	(19)	105	(67)	127
Net Loss	(4,786)	364	(9,217)	2,593
Reclassification Out of Accumulated Other Comprehensive Income (Loss) | Defined Benefit Pension Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax effect of net (loss) gain	(23)	742	11	1,452
Net Loss	(3,968)	(1,124)	(5,792)	(2,279)
Amortization of prior service credit (cost)	502	(7)	1,003	(15)
Recognized actuarial loss	(2,046)	(1,859)	(4,363)	(3,716)
Loss Before Income Taxes	(3,945)	(1,866)	(5,803)	(3,731)
Other non-operating income/expense | Reclassification Out of Accumulated Other Comprehensive Income (Loss) | Defined Benefit Pension Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Settlement loss	$ (2,401)	$ 0	$ (2,443)	$ 0