Quarterly report pursuant to Section 13 or 15(d)

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

v3.8.0.1
Goodwill and Intangible Assets, Net of Accumulated Amortization (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended
Aug. 31, 2017
Aug. 31, 2016
May 31, 2017
Goodwill and Intangible Assets, Net of Accumulated Amortization [Abstract]      
Goodwill $ 698.0   $ 657.1
Increased in goodwill result of HROI acquisition 40.9    
Amortization expense $ 3.9 $ 4.4