Quarterly report pursuant to Section 13 or 15(d)

Investment Income, Net (Schedule of Investment Income, Net) (Details)

v3.6.0.2
Investment Income, Net (Schedule of Investment Income, Net) (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Nov. 30, 2016
Nov. 30, 2015
Nov. 30, 2016
Nov. 30, 2015
Investment Income, Net [Abstract]        
Interest income on corporate funds $ 2.4 $ 2.1 $ 4.8 $ 4.0
Interest expense (0.6) (0.3) (1.3) (0.5)
Net loss from equity-method investments (0.9) (0.2) (1.1) (0.5)
Investment income, net $ 0.9 $ 1.6 $ 2.4 $ 3.0