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Property, Plant and Equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Property, Plant and Equipment, net
Property, plant and equipment, gross	$ 294,952		$ 294,952		$ 282,688
Accumulated depreciation and amortization	(204,586)		(204,586)		(190,007)
Property, plant and equipment, net	90,366		90,366		92,681
Depreciation expense	6,100	$ 6,200	18,400	$ 18,300
Land
Property, Plant and Equipment, net
Property, plant and equipment, gross	2,776		2,776		2,724
Buildings and improvements
Property, Plant and Equipment, net
Property, plant and equipment, gross	25,057		$ 25,057		25,731
Buildings and improvements | Minimum
Property, Plant and Equipment, net
Useful Life (Years)			30 years
Buildings and improvements | Maximum
Property, Plant and Equipment, net
Useful Life (Years)			40 years
Office furniture and equipment
Property, Plant and Equipment, net
Property, plant and equipment, gross	20,697		$ 20,697		19,902
Office furniture and equipment | Minimum
Property, Plant and Equipment, net
Useful Life (Years)			5 years
Office furniture and equipment | Maximum
Property, Plant and Equipment, net
Useful Life (Years)			8 years
Machinery and equipment
Property, Plant and Equipment, net
Property, plant and equipment, gross	$ 246,422		$ 246,422		$ 234,331
Machinery and equipment | Minimum
Property, Plant and Equipment, net
Useful Life (Years)			5 years
Machinery and equipment | Maximum
Property, Plant and Equipment, net
Useful Life (Years)			7 years

X

- Definition

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Amount of accumulated depreciation and amortization from plant, property, and equipment and right-of-use asset from finance lease.

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