Income Taxes - Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2021	Aug. 31, 2020	Aug. 31, 2019
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefit – Opening Balance	$ 5,502	$ 1,605	$ 1,608
Gross increases – tax positions in prior period		4,034
Gross decreases – tax positions in prior period	(3,602)		(3)
Lapse of statute of limitations	(335)	(137)
Unrecognized Tax Benefit – Ending Balance	$ 1,565	$ 5,502	$ 1,605