Property, Plant and Equipment, Net - Summary (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 461,323	$ 438,619
Accumulated depreciation	(265,586)	(244,098)
Accumulated depreciation of finance leases	(143)	(608)
Property and equipment, net excluding work in progress	195,594	193,913
Construction in progress	26,048	19,456
Total property, plant and equipment, net	221,642	213,369
Depreciation expense	27,100	23,400	$ 21,400
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	6,268	6,280
Land | Assets Held under Finance Leases
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	225	228
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 107,721	104,036
Buildings and improvements | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	10 years
Buildings and improvements | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	35 years
Buildings and improvements | Assets Held under Finance Leases
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 0	229
Buildings and improvements | Assets Held under Finance Leases | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	2 years
Buildings and improvements | Assets Held under Finance Leases | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	10 years
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 308,457	289,059
Machinery and equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	5 years
Machinery and equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	25 years
Machinery and equipment | Assets Held under Finance Leases
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 200	1,005
Machinery and equipment | Assets Held under Finance Leases | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	8 years
Machinery and equipment | Assets Held under Finance Leases | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	10 years
Office equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 36,905	36,110
Office equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	2 years
Office equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	8 years
Office equipment | Assets Held under Finance Leases
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 31	32
Property, plant and equipment useful life	5 years
Vehicles
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 1,516	$ 1,640
Vehicles | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	3 years
Vehicles | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	6 years