Quarterly report pursuant to Section 13 or 15(d)

Goodwill and Intangible Assets, Net of Accumulated Amortization (Narrative) (Details)

v3.6.0.2
Goodwill and Intangible Assets, Net of Accumulated Amortization (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Nov. 30, 2016
Nov. 30, 2015
Nov. 30, 2016
Nov. 30, 2015
May 31, 2016
Goodwill and Intangible Assets, Net of Accumulated Amortization [Abstract]          
Goodwill $ 657.1   $ 657.1   $ 657.1
Amortization expense $ 4.5 $ 3.0 $ 8.9 $ 6.0