Equity - Summary of Restricted Stock Share and Restricted Stock Unit Grant Transactions for Shares, both Vested and Unvested (Detail) - shares		12 Months Ended
		Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2016
Reconciliation of Restricted Stock Activity [Line Items]
Beginning Balance	[1]	4,091,729	3,848,230	3,419,861
Granted		317,036	269,705	447,895
Forfeited		(34,440)	(26,206)	(19,526)
Ending Balance	[1]	4,374,325	4,091,729	3,848,230

[1] Balance represents cumulative grants net of forfeitures.