Employee Benefit and Retirement Plans-Components of Other Postretirement Benefit Expenses (Details) (Other postretirement benefits [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2012	Aug. 31, 2011
Other postretirement benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 0.9	$ 1.0	$ 3.0	$ 2.9
Interest costs	1.1	1.1	3.6	3.3
Amortization of prior service costs	(1.0)	(1.5)	(3.0)	(4.5)
Amortization of losses	(0.1)	0.2	0	0.6
Total other postretirement expense	$ 0.9	$ 0.8	$ 3.6	$ 2.3