Annual report pursuant to Section 13 and 15(d)

Capital Stock Share Repurchases - Additional Information (Details)

v3.20.2
Capital Stock Share Repurchases - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Aug. 31, 2020
Aug. 31, 2019
Mar. 16, 2015
Oct. 01, 2014
Mar. 29, 2014
Sep. 28, 2011
Capital Unit [Line Items]            
Common stock, shares authorized 168,000,000 168,000,000        
Common stock, par value $ 0.20 $ 0.20        
Common stock, shares issued 82,593,945 81,920,679        
Cumulative Preferred Stock, shares authorized share 160,000          
Cumulative Preferred Stock, par value $ 1.00          
Cumulative Preferred Stock, issued 0          
Shares authorized in buyback program     7,000,000 7,000,000 7,000,000 7,000,000
Treasury stock, shares 22,799,230 21,455,568        
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased 5,200,770          
Stock Repurchased During Period, Shares 1,343,662          
Stock Repurchased During Period, Value $ 27.5          
Common Class A            
Capital Unit [Line Items]            
Common stock, shares authorized 168,000,000          
Common stock, par value $ 0.20          
Common stock, shares issued 82,593,945          
Common stock, shares outstanding 59,794,715          
Common Class B            
Capital Unit [Line Items]            
Common stock, shares authorized 1,500,000          
Common stock, par value $ 0.20          
Common stock, shares issued 0          
Common stock, shares outstanding   0