Annual report pursuant to Section 13 and 15(d)

Stocks Plans - Additional Information (Detail)

v3.20.2
Stocks Plans - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Aug. 31, 2020
Aug. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Class A Common Stock were authorized for issuance 4,325,000  
Common Stock Registered to Cover Shares that Become Issuable 1,800,000  
Shares available for future grants 2,362,855  
Exercise price as percentage of fair market value at grant date 100.00%  
Unrecognized compensation cost related to share-based compensation for stock options and restricted stock outstanding $ 13.6  
Unrecognized compensation cost related to share-based compensation for stock options and restricted stock outstanding, recognition period 1 year 9 months 18 days  
Performance Shares    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Performance period 3 years  
Performance Shares | Free Cash Flow Conversion Target    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage 50.00%  
Performance Shares | Total Shareholders Return    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage 50.00%  
Restricted Stock    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Fair value of shares vested $ 18.2 $ 11.9
After Three Years    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage 50.00%  
After Five Years    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage 100.00%  
Maximum | Stock Options    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock options term 10 years