Goodwill and Other Intangibles (Detail) - Schedule of other intangible assets subject to amortization (USD $) In Millions, unless otherwise specified	9 Months Ended		12 Months Ended
	Feb. 28, 2013	Feb. 29, 2012	May 31, 2012
Amortization expense	$ 1.9	$ 1.3
Total other intangibles subject to amortization	13.0	16.2	14.7
Customer Lists [Member]
Begining balance	4.3	0.7	0.7
Additions due to acquisition	0.1		3.8
Amortization expense	(0.7)	(0.2)	(0.2)
Foreign currency translation	0	0	0
Intangibles, net of accumulated amortization	3.7	0.5	4.3
Accumulated amortization	2.0	1.3	1.3
Other Intangible Assets [Member]
Begining balance	10.4	17.3	17.3
Impairment charge		(0.5)	(5.4)
Amortization expense	(1.2)	(1.1)	(1.4)
Other	0.1		(0.1)
Intangibles, net of accumulated amortization	9.3	15.7	10.4
Accumulated amortization	$ 11.7	$ 5.3	$ 10.5