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, 2011	Nov. 30, 2010	May 31, 2011
Beginning balance	$ 18.0
Amortization expense	0.9	0.6	1.4
Total other intangibles subject to amortization	17.1	13.2	18.0
Customer Lists [Member]
Beginning balance	0.7	0.8	0.8
Amortization expense	(0.1)	(0.1)	(0.2)
Foreign currency translation	0	0.1	0.1
Total other intangibles subject to amortization	0.6	0.8	0.7
Other Intangible Assets [Member]
Beginning balance	17.3	2.2	2.2
Additions due to acquisition			5.6
Reclassified from indefinite-lived intangible assets		10.7	10.7
Amortization expense	(0.8)	(0.5)	(1.2)
Total other intangibles subject to amortization	$ 16.5	$ 12.4	$ 17.3