XML 59 R48.htm IDEA: XBRL DOCUMENT v3.6.0.2
Employee Benefit Plans - Schedule of net periodic costs (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Nov. 30, 2016
Nov. 30, 2015
Nov. 30, 2016
Nov. 30, 2015
Components of net periodic benefit (credit) cost:        
Amortization of (gain) loss     $ 2.1 $ 2.2
Pension Plans        
Components of net periodic benefit (credit) cost:        
Service cost $ 0.0 $ 0.0 0.0 0.0
Interest cost 1.1 1.6 2.2 3.1
Expected return on assets (1.8) (2.0) (3.6) (3.9)
Net amortization of prior service credit 0.0 0.0 0.0 0.0
Amortization of (gain) loss 0.5 0.4 0.9 0.8
Net periodic benefit (credit) cost (0.2) 0.0 (0.5) 0.0
Post-Retirement Benefits        
Components of net periodic benefit (credit) cost:        
Service cost 0.0 0.0 0.0 0.0
Interest cost 0.3 0.4 0.6 0.7
Expected return on assets 0.0 0.0 0.0 0.0
Net amortization of prior service credit 0.0 0.0 0.0 0.0
Amortization of (gain) loss 0.6 0.8 1.2 1.4
Net periodic benefit (credit) cost $ 0.9 $ 1.2 $ 1.8 $ 2.1