Property, Plant and Equipment, net (Schedule of Property, Plant and Equipment) (Details) - USD ($) $ in Thousands	4 Months Ended	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Aug. 31, 2023
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,734,723	$ 1,734,723	$ 1,504,037
Accumulated depreciation and amortization	(1,132,734)	(1,132,734)	(1,058,379)
Property, plant and equipment, net	601,989	601,989	445,658	$ 436,417
Depreciation expense		70,374	62,480	65,130
Software, amortization		1,900	1,700	1,900
Capital expenditures and purchased software		84,429	96,348	53,699
Unamortized software cost	6,600	6,600	5,900	3,900
Expenditures for maintenance and repairs		22,400	20,700	$ 19,300
Heimbach
Property, Plant and Equipment [Line Items]
Property, plant and equipment					$ 125,117
Depreciation expense	4,000	4,000
Minimum | Heimbach | Foreign Bank Debt
Property, Plant and Equipment [Line Items]
Interest rate, stated percentage					0.98%
Maximum | Heimbach | Foreign Bank Debt
Property, Plant and Equipment [Line Items]
Interest rate, stated percentage					5.52%
Land and land improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 29,654	$ 29,654	14,059
Useful life	25 years	25 years
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 302,086	$ 302,086	247,136
Buildings | Minimum
Property, Plant and Equipment [Line Items]
Useful life	15 years	15 years
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Useful life	40 years	40 years
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,207,504	$ 1,207,504	1,053,700
Machinery and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life	5 years	5 years
Machinery and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life	15 years	15 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 11,409	$ 11,409	8,158
Useful life	5 years	5 years
Computer and other equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 24,120	$ 24,120	21,570
Computer and other equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life	3 years	3 years
Computer and other equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life	10 years	10 years
Software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 69,191	$ 69,191	66,794
Software | Minimum
Property, Plant and Equipment [Line Items]
Useful life	5 years	5 years
Software | Maximum
Property, Plant and Equipment [Line Items]
Useful life	8 years	8 years
Capital expenditures in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 90,759	$ 90,759	$ 92,620