Other Financial Statement Information - Property, Plant and Equipment - Net (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment - Gross	$ 286,135	$ 261,702
Less accumulated depreciation	(168,438)	(158,747)
Property, plant and equipment - Net	117,697	102,955
Land and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment - Gross	18,380	12,552
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment - Gross	81,896	74,743
Machinery, Equipment and Aircraft [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment - Gross	179,503	171,015
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment - Gross	$ 6,356	$ 3,392