Components of Accumulated Other Comprehensive Loss Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	$ 55,606	$ 49,520	$ 110,747	$ 100,304
Interest Expense	12,405	13,805	24,058	26,168
Income (loss) from continuing operations before income taxes and equity income (loss)	30,562	(13,428)	47,329	(28,042)
Income tax expense	11,234	12,000	17,487	9,834
Net income (loss)	19,731	(24,301)	29,868	(33,893)
Amount Reclassified from Accumulated Other Comprehensive Loss
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense				(1,776)
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)	5,566	4,574	11,086	9,224
Income tax expense	(522)	(517)	(1,044)	(1,034)
Net income (loss)	5,044	4,057	10,042	8,190
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)	65	280	308	(185)
Income tax expense	(29)	(109)	(123)	56
Net income (loss)	36	171	185	(129)
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	(189)	0	(189)	(408)
Cost of services and products sold	3	(1)	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	251	281	493	224
Amount Reclassified from Accumulated Other Comprehensive Loss | Actuarial losses
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	2,706	2,285	5,358	4,661
Cost of services and products sold	2,806	2,229	5,621	4,443
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	(10)	(3)	(22)	(4)
Cost of services and products sold	$ 64	$ 63	$ 129	$ 124