Summary of Significant Accounting Policies - Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2016
Allowance for doubtful accounts
Balance at beginning of period	$ 1,768	$ 2,215	$ 2,449
Additions, net of reversals	938	370	70
Usage	(54)	(891)	(277)
Currency translation effect	49	74	(27)
Balance at end of period	$ 2,701	$ 1,768	$ 2,215