Annual report pursuant to Section 13 and 15(d)

Weighted-Average Assumptions (Detail)

v3.8.0.1
Weighted-Average Assumptions (Detail)
12 Months Ended
Aug. 31, 2017
Aug. 31, 2016
Aug. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]      
Dividend yield 0.15062% 0.18918% 0.15%
Expected volatility 38.1247% 38.06236% 37.80%
Risk-free rate of return 2.41666% 2.06317% 1.19%
Expected forfeiture rate 11.00% 13.12% 13.73%
Expected life 7 years 7 months 9 days 6 years 1 month 6 years 1 month