Quarterly report pursuant to Section 13 or 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
3 Months Ended
Aug. 31, 2018
Aug. 31, 2017
Equity, Class of Treasury Stock [Line Items]    
Common stock issued in connection with exercise or vesting of stock-based awards 0.5 0.5
Common stock issued related to acquisition   0.6
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 0.5 1.6
Common stock repurchased and retired, values $ 32.8 $ 94.1