Components of Accumulated Other Comprehensive Loss Dilution of Equity Method Investment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax expense	$ 8,270	$ 5,079	$ 25,757	$ 14,913
Amount Reclassified from Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax		40,752		45,565
Income tax expense		(15,046)		(16,822)
Total amounts reclassified from accumulated other comprehensive loss in connection with loss on dilution of equity method investment		25,706		28,743
Amount Reclassified from Accumulated Other Comprehensive Loss | Foreign exchange translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax		40,525		45,405
Amount Reclassified from Accumulated Other Comprehensive Loss | Cash flow hedging instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax		2,425		2,593
Amount Reclassified from Accumulated Other Comprehensive Loss | Defined benefit pension obligations
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax		$ (2,198)		$ (2,433)