Restructuring (Tables)
 9 Months Ended
Feb. 28, 2014
Restructuring and Related Activities [Abstract]  
Summary of severance and benefit costs
A summary of the severance and benefit costs in the periods presented is as follows:
 (in millions)
Employee Severance and Benefit Costs
 Restructuring Accrual:
 
 Balance at May 31, 2013
$
8.9

      Costs incurred and charged to expense
6.3

      Costs paid or otherwise settled
(5.3
)
      Non-cash adjustments(1)
0.7

 Balance at August 31, 2013
10.6

      Costs incurred and charged to expense
5.9

      Costs paid or otherwise settled
(3.9
)
      Non-cash adjustments(1)
0.8

 Balance at November 30, 2013
13.4

      Costs incurred and charged to expense
6.6

      Costs paid or otherwise settled
(2.1
)
      Non-cash adjustments(1)
0.8

 Balance at February 28, 2014
$
18.7

(1)
Primarily related to foreign currency fluctuations.

 (in millions)
Employee Severance and Benefit Costs
 Restructuring Accrual:
 
 Balance at May 31, 2012
$
9.5

      Costs incurred and charged to expense
1.1

      Costs paid or otherwise settled
(0.4
)
      Non-cash adjustments(1)
0.1

 Balance at August 31, 2012
10.3

      Costs incurred and charged to expense
1.0

      Costs paid or otherwise settled
(1.6
)
      Non-cash adjustments(1)
0.1

 Balance at November 30, 2012
9.8

      Costs incurred and charged to expense
1.9

      Costs paid or otherwise settled
(2.3
)
      Non-cash adjustments(1)
(0.4
)
 Balance at February 28, 2013
$
9.0

(1)
Primarily related to foreign currency fluctuations.