Income Taxes - Schedule of Income Tax Provision (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended	12 Months Ended
May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2010
Current
U.S. federal			$ 5.7	$ 2.4	$ 10.9	$ 2.0	$ (5.2)
State and local			1.7	1.1	3.8	4.2	3.1
Current income tax provision (benefit)					14.7	6.2	(2.1)
Deferred
U.S. federal					3.2	(0.4)	(0.8)
State and local					1.0	0.3	(1.0)
Deferred income tax provision (benefit)			1.6	2.1	4.2	(0.1)	(1.8)
Income tax provision (benefit)	$ 2.1	$ 3.3	$ 7.0	$ 5.6	$ 18.9	$ 6.1	$ (3.9)

Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred federal income tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred state and local tax expense (benefit) pertaining to income (loss) from continuing operations.