Components of Net Periodic Benefit Costs (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	May 31, 2012	May 31, 2011	May 31, 2012	May 31, 2011
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service costs	$ 0.4	$ 0.5	$ 0.8	$ 1.0
Interest costs	3.5	3.4	7.1	6.9
Expected return on plan assets	(3.6)	(3.7)	(7.2)	(7.6)
Amortization of net actuarial loss (gain)	0.8	0.7	1.6	1.4
Net periodic cost (benefit)	1.1	0.9	2.3	1.7
Health Care Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest costs	0.1	0.1	0.3	0.2
Amortization of net actuarial loss (gain)	(0.3)	(0.4)	(0.7)	(0.8)
Amortization of prior service costs	(0.1)	(0.1)	(0.2)	(0.1)
Net periodic cost (benefit)	$ (0.3)	$ (0.4)	$ (0.6)	$ (0.7)