Quarterly report pursuant to Section 13 or 15(d)

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

v3.7.0.1
Basic and Diluted Earnings Per Share (Narrative) (Details) - USD ($)
shares in Millions, $ in Millions
3 Months Ended 9 Months Ended
Feb. 28, 2017
Feb. 29, 2016
Feb. 28, 2017
Feb. 29, 2016
Equity, Class of Treasury Stock [Line Items]        
Common stock repurchased and retired, shares 0.0   2.9  
Common stock repurchased and retired, values     $ 166.2  
Authorized in May 2014 [Member]        
Equity, Class of Treasury Stock [Line Items]        
Expiration date     May 31, 2017  
Approved repurchase amount $ 350.0   $ 350.0  
Common stock repurchased and retired, shares   0.9   2.2
Common stock repurchased and retired, values   $ 45.0 $ 59.7 $ 107.9
Authorized in July 2016 [Member]        
Equity, Class of Treasury Stock [Line Items]        
Expiration date     May 31, 2019  
Approved repurchase amount $ 350.0   $ 350.0  
Common stock repurchased and retired, values     $ 106.5  
Common Stock [Member]        
Equity, Class of Treasury Stock [Line Items]        
Common stock issued in connection with exercise or vesting of stock-based awards 0.4 0.1 1.8 1.2