Components of Accumulated Other Comprehensive Loss - Reclassification out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other Operating Income (Expense), Net	$ (5,733)	$ (1,743)
Product revenues	398,841	329,902
Interest expense	12,649	5,507
Income from continuing operations before income taxes	(8,474)	13,512
Income tax expense (benefit)	(682)	1,219
Net income	1,227	22,537
Amount Reclassified from Accumulated Other Comprehensive Loss | Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other Operating Income (Expense), Net	0
Amount Reclassified from Accumulated Other Comprehensive Loss | Cumulative Unrecognized Actuarial Losses on Pension Obligations
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations before income taxes	10,550	5,124
Income tax expense (benefit)	(1,710)	(342)
Net income	8,840	4,782
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 from continuing operations before income taxes	(721)	(19)
Income tax expense (benefit)	76	(44)
Net income	(645)	(63)
Amount Reclassified from Accumulated Other Comprehensive Loss | Effective Portion of Deriviatives Designated as Hedging Instruments | Foreign currency exchange forward contracts
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other Operating Income (Expense), Net		(2,271)
Discontinued Operation, Gain From Disposal Of Discontinued Operation, Before Income Tax	12,906	0
Product revenues	(1,404)	(32)
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	305	314
Amount Reclassified from Accumulated Other Comprehensive Loss | Effective Portion of Deriviatives Designated as Hedging Instruments | Interest rate swaps
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	378	(301)
Amount Reclassified from Accumulated Other Comprehensive Loss | Actuarial losses
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Defined benefit pension income (expense)	5,080	5,058
Amount Reclassified from Accumulated Other Comprehensive Loss | Prior service costs (benefits)
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Defined benefit pension income (expense)	5,363
Amount Reclassified from Accumulated Other Comprehensive Loss | Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Defined benefit pension income (expense)	$ 107	$ 66