Interim Financial Statements - Additional Information (Detail) - USD ($)	6 Months Ended
	Feb. 28, 2017	Feb. 29, 2016	Aug. 31, 2016	Oct. 31, 2013
Equity, Class of Treasury Stock [Line Items]
Intangibles and other assets, net	$ 68,228,000		$ 67,359,000
Notes payable	$ 532,596,000		301,853,000
Stock repurchase program total cost of repurchased shares		$ 32,373,000
Accounting Standards Update 2015-03 | Reclassifications
Equity, Class of Treasury Stock [Line Items]
Intangibles and other assets, net			(2,100,000)
Notes payable			$ 2,100,000
Share Repurchase Program - 2014
Equity, Class of Treasury Stock [Line Items]
Stock repurchased during period, shares	0
Stock repurchase program total cost of repurchased shares	$ 137,000,000
Repurchase of common stock, shares	3,206,226
Remaining authorized repurchase amount	$ 88,000,000
Repurchase program expiration date	Jan. 01, 2018
Maximum | Share Repurchase Program - 2013
Equity, Class of Treasury Stock [Line Items]
Amount authorized for repurchase				$ 225,000,000