Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Aug. 31, 2020	Aug. 31, 2019
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	$ 168,247	$ 159,389
Accumulated depreciation	(110,389)	(102,437)
Total operating property, plant, and equipment, net	57,858	56,952
Machines	12,457	8,861
Barriers	27,403	20,445
Total property held for lease	39,860	29,306
Accumulated depreciation	(18,137)	(17,290)
Total property held for lease, net	21,723	12,016
Property, plant, and equipment, net	79,581	68,968
Land [Member]
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	2,639	2,775
Building [Member]
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	40,730	41,284
Machinery And Equipment [Member]
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	85,185	77,715
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	8,089	7,706
Computer Hardware and Software [Member]
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	20,927	18,956
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	$ 10,677	$ 10,953