Annual report pursuant to Section 13 and 15(d)

Weighted-Average Assumptions (Detail)

v3.3.0.814
Weighted-Average Assumptions (Detail)
12 Months Ended
Aug. 31, 2015
Aug. 31, 2014
Aug. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]      
Dividend yield 0.15% 0.11% 0.14%
Expected volatility 37.80% 38.30% 38.36%
Risk-free rate of return 1.19% 0.70% 0.84%
Expected forfeiture rate 13.73% 14.18% 15.00%
Expected life 6 years 1 month 6 years 1 month 6 years 1 month