Goodwill and Other Intangibles (Details) - Schedule of other intangible assets subject to amortization (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	May 31, 2013
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 0.6	$ 0.5
Total other intangibles subject to amortization	12.0	14.4	12.6
Trademarks and other	2.0	2.0	2.0
Total other intangibles not subject to amortization	2.0	2.0	2.0
Total other intangibles	14.0	16.4	14.6
Customer Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Begining balance	3.4	4.3	4.3
Additions due to acquisition		0.1	0.1
Amortization expense	(0.2)	(0.2)	(1.0)
Foreign currency translation	0	0	0
Total other intangibles subject to amortization	3.2	4.2	3.4
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Begining balance	9.2	10.4	10.4
Additions due to acquisition			0.2
Amortization expense	(0.4)	(0.3)	(1.5)
Foreign currency translation	0
Other		0.1	0.1
Total other intangibles subject to amortization	$ 8.8	$ 10.2	$ 9.2