Goodwill and Other Intangibles (Detail) - Schedule of other intangible assets subject to amortization (USD $) In Millions, unless otherwise specified	6 Months Ended		12 Months Ended
	Nov. 30, 2012	Nov. 30, 2011	May 31, 2012
Amortization expense	$ 1.3	$ 0.9
Total other intangibles subject to amortization	13.6	17.1	14.7
Customer Lists [Member]
Begining balance	4.3	0.7	0.7
Additions due to acquisition	0.1		3.8
Amortization expense	(0.5)	(0.1)	(0.2)
Foreign currency translation	0	0	0
Total other intangibles subject to amortization	3.9	0.6	4.3
Other Intangible Assets [Member]
Begining balance	10.4	17.3	17.3
Impairment charge			(5.4)
Amortization expense	(0.8)	(0.8)	(1.4)
Other	0.1		(0.1)
Total other intangibles subject to amortization	$ 9.7	$ 16.5	$ 10.4