Quarterly report pursuant to Section 13 or 15(d)

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

v3.7.0.1
Goodwill and Intangible Assets, Net of Accumulated Amortization (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Feb. 28, 2017
Feb. 29, 2016
Feb. 28, 2017
Feb. 29, 2016
May 31, 2016
Goodwill and Intangible Assets, Net of Accumulated Amortization [Abstract]          
Goodwill $ 657.1   $ 657.1   $ 657.1
Amortization expense $ 4.6 $ 5.3 $ 13.5 $ 11.3