Balance Sheet Components - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Nov. 30, 2017	Aug. 31, 2017
Property Plant And Equipment [Line Items]
Total property, plant and equipment	$ 59,692	$ 59,323
Less: Accumulated depreciation and amortization	(51,593)	(51,048)
Property, plant and equipment, net	8,099	8,275
Buildings and improvements
Property Plant And Equipment [Line Items]
Total property, plant and equipment	13,979	13,891
Machinery and equipment
Property Plant And Equipment [Line Items]
Total property, plant and equipment	42,845	42,562
Leasehold improvements
Property Plant And Equipment [Line Items]
Total property, plant and equipment	240	238
Other equipment
Property Plant And Equipment [Line Items]
Total property, plant and equipment	2,324	2,311
Construction in progress
Property Plant And Equipment [Line Items]
Total property, plant and equipment	$ 304	$ 321