Restructuring Related Balance Sheet Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve - Beginning Balance	$ 47,970
Costs incurred and charged to expense	6,418	$ 49,090	$ (7,263)
Cash receipts (payments)	(17,402)
Net assets disposed and impaired	1,407
Effect of change in exchange rates	4,546
Restructuring Reserve - Ending Balance	40,125	47,970
Employee severance costs
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve - Beginning Balance	45,368
Costs incurred and charged to expense	169
Cash receipts (payments)	(12,423)
Net assets disposed and impaired	0
Effect of change in exchange rates	4,540
Restructuring Reserve - Ending Balance	37,654	45,368
Asset Impairment and Net (Gain) Loss on Sale or Disposal [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve - Beginning Balance	0
Costs incurred and charged to expense	(2,297)
Cash receipts (payments)	3,704
Net assets disposed and impaired	1,407
Effect of change in exchange rates	0
Restructuring Reserve - Ending Balance	0	0
Other restructuring costs
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve - Beginning Balance	2,602
Costs incurred and charged to expense	8,546
Cash receipts (payments)	(8,683)
Net assets disposed and impaired	0
Effect of change in exchange rates	6
Restructuring Reserve - Ending Balance	$ 2,471	$ 2,602