Annual report pursuant to Section 13 and 15(d)

Capital Stock Share Repurchases - Additional Information (Details)

v3.8.0.1
Capital Stock Share Repurchases - Additional Information (Details) - $ / shares
Aug. 31, 2017
Aug. 31, 2016
Mar. 16, 2015
Oct. 01, 2014
Mar. 29, 2014
Sep. 28, 2011
Capital Unit [Line Items]            
Common stock, shares authorized 168,000,000          
Common stock, par value $ 0.20          
Common stock, shares issued 80,200,110 79,393,393        
Cumulative Preferred Stock, shares authorized share 160,000          
Cumulative Preferred Stock, par value $ 1          
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 20,439,434 20,439,434        
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased 7,560,566          
Common Class A            
Capital Unit [Line Items]            
Common stock, shares authorized 168,000,000          
Common stock, par value $ 0.2          
Common stock, shares issued 80,200,110          
Common stock, shares outstanding 59,760,676          
Common Class B            
Capital Unit [Line Items]            
Common stock, shares authorized 1,500,000          
Common stock, par value $ 0.2          
Common stock, shares issued 0          
Common stock, shares outstanding   0