XML 113 R91.htm IDEA: XBRL DOCUMENT v3.10.0.1
Earnings Per Share - Reconciliation of Shares Used in Computation of Basic and Diluted Earnings Per Common Share (Parenthetical) (Detail) - shares
12 Months Ended
Aug. 31, 2018
Aug. 31, 2017
Aug. 31, 2016
2018 Senior Notes      
Earnings Per Share Disclosure [Line Items]      
Debt instrument, maturity date Apr. 01, 2018    
Restricted Stock      
Earnings Per Share Disclosure [Line Items]      
Anti-dilutive shares excluded from calculation 0 0 0