Components of Accumulated Other Comprehensive Loss Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	$ 61,221	$ 50,249	$ 171,968	$ 150,553
Interest Expense	12,123	13,756	36,181	39,924
Income (loss) from continuing operations before income taxes and equity income (loss)	22,437	(29,295)	69,766	(57,337)
Income tax expense	8,270	5,079	25,757	14,913
Net income (loss)	13,796	(31,544)	43,664	(65,437)
Amount Reclassified from Accumulated Other Comprehensive Loss
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense		(15,046)		(16,822)
Amount Reclassified from Accumulated Other Comprehensive Loss | Cumulative Unrecognized Actuarial Losses on Pension Obligations
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from continuing operations before income taxes and equity income (loss)	5,614	4,579	16,699	13,803
Income tax expense	(523)	(601)	(1,566)	(1,635)
Net income (loss)	5,091	3,978	15,133	12,168
Amount Reclassified from Accumulated Other Comprehensive Loss | Effective Portion of Deriviatives Designated as Hedging Instruments
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from continuing operations before income taxes and equity income (loss)	252	254	560	69
Income tax expense	(99)	(99)	(222)	(43)
Net income (loss)	153	155	338	26
Amount Reclassified from Accumulated Other Comprehensive Loss | Effective Portion of Deriviatives Designated as Hedging Instruments | Foreign currency forward exchange contracts
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Revenues	0	0	(189)	(408)
Cost of services and products sold	0	0	4	(1)
Amount Reclassified from Accumulated Other Comprehensive Loss | Effective Portion of Deriviatives Designated as Hedging Instruments | Cross currency interest rate swaps
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Interest Expense	252	254	745	478
Amount Reclassified from Accumulated Other Comprehensive Loss | Actuarial losses
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	2,643	2,042	8,001	6,703
Cost of services and products sold	2,915	2,253	8,535	6,696
Amount Reclassified from Accumulated Other Comprehensive Loss | Prior service costs (benefits)
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	(14)	(5)	(36)	(9)
Cost of services and products sold	70	66	199	190
Amount Reclassified from Accumulated Other Comprehensive Loss | Settlement/curtailment losses
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	$ 0	$ 223	$ 0	$ 223