Annual report pursuant to Section 13 and 15(d)

Basic and Diluted Earnings Per Share (Narrative) (Details)

v3.10.0.1
Basic and Diluted Earnings Per Share (Narrative) (Details) - USD ($)
shares in Millions, $ in Millions
1 Months Ended 12 Months Ended
Jul. 31, 2016
May 31, 2018
May 31, 2017
May 31, 2016
Equity, Class of Treasury Stock [Line Items]        
Common stock repurchased and retired, shares     2.9  
Common stock repurchased and retired, values   $ 143.1 $ 166.2 $ 107.9
Authorized in July 2016 [Member]        
Equity, Class of Treasury Stock [Line Items]        
Expiration date May 31, 2019      
Approved repurchase amount $ 350.0      
Common stock repurchased and retired, shares   2.5    
Common stock repurchased and retired, values   $ 143.1    
Previously Authorized Repurchase Program [Member]        
Equity, Class of Treasury Stock [Line Items]        
Common stock repurchased and retired, values     $ 59.7