Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2014	Aug. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1.5	$ 3.4	$ 4.5	$ 9.7
Stock Appreciation Rights [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	(0.6)	1.3	(1.1)	6.0
Stock Options [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	0.1	0.3	0.2	0.3
Restricted Shares, Service Based [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	1.0	0.5	3.2	1.7
Restricted Shares, Performance Based [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1.0	$ 1.3	$ 2.2	$ 1.7