Accrued Severance (Details) - Schedule of accrued severance cost associated with cost reduction measures (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	May 31, 2013
Schedule of accrued severance cost associated with cost reduction measures [Abstract]
Beginning balance	$ 3.3	$ 2.7	$ 2.7
Accruals	2.3	1.3	13.4
Payments	(3.6)	(2.9)	(12.8)
Ending balance	$ 2.0	$ 1.1	$ 3.3