Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Aug. 31, 2019	Aug. 31, 2018
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	$ 159,389	$ 145,114
Accumulated depreciation	(102,437)	(98,191)
Total operating property, plant, and equipment, net	56,952	46,923
Machines	8,861	8,214
Barriers	20,445	18,122
Total property held for lease	29,306	26,336
Accumulated depreciation	(17,290)	(16,011)
Total property held for lease, net	12,016	10,325
Property, plant, and equipment, net	68,968	57,248
Land [Member]
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	2,775	2,799
Building [Member]
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	41,284	37,220
Machinery And Equipment [Member]
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	77,715	75,635
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	7,706	6,632
Computer Hardware and Software [Member]
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	18,956	16,095
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Total operating property, plant and equipment	$ 10,953	$ 6,733