Inventory Valuation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	$ 3,257
Balance at end of period	4,136	$ 3,257
Inventory Valuation Reserve
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	3,257	2,679	$ 2,866
Charge to cost of revenue	2,781	2,422	2,564
Disposition of inventory	(2,003)	(1,792)	(2,434)
Currency translation effect	101	(52)	(317)
Balance at end of period	$ 4,136	$ 3,257	$ 2,679