Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Income Taxes [Line Items]
Unrecognized Tax Benefit - Opening Balance	$ 942	$ 1,019	$ 1,030
Gross increases - tax positions in prior period	1,368
Gross decreases - tax positions in prior period	(53)
Settlements	0	0	0
Lapse of statute of limitations	(437)	(77)	(11)
Unrecognized Tax Benefit - Ending Balance	$ 1,820	$ 942	$ 1,019