Components of Accumulated Other Comprehensive Loss - Reclassification out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Product revenues	$ 544,301			$ 509,398			$ 1,642,976	$ 1,355,520
Interest expense	16,004			15,794			48,854	43,396
Income from continuing operations before income taxes	18,242			(8,267)			50,277	(28,719)
Income tax expense (benefit)	6,989			(1,654)			19,782	(4,640)
Net income (loss)	9,828	$ 15,080	$ 1,565	(8,339)	$ (9,455)	$ 1,227	26,473	(16,567)
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	6,047			5,075			18,258	20,488
Income tax expense (benefit)	(358)			(323)			(1,074)	(2,356)
Net income (loss)	5,689			4,752			17,184	18,132
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	454			1,225			2,134	1,199
Income tax expense (benefit)	(148)			(408)			(646)	(595)
Net income (loss)	306			817			1,488	604
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]
Discontinued Operation, Gain From Disposal Of Discontinued Operation, Before Income Tax	0			0			0	12,906
Product revenues	(418)			174			(465)	(1,562)
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	0			312			0	912
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	872			739			2,599	1,849
Amount Reclassified from Accumulated Other Comprehensive Loss | Actuarial losses
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Defined benefit pension income	5,922			4,962			17,877	14,799
Amount Reclassified from Accumulated Other Comprehensive Loss | Prior service costs
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Defined benefit pension income	125			113			381	326
Amount Reclassified from Accumulated Other Comprehensive Loss | Pension liability transfer - discontinued business
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Defined benefit pension income	$ 0			$ 0			$ 0	$ 5,363