(Loss) Income Per Share of Common Stock - Reconciliation of Numerator and Denominator Used to Calculate Basic and Diluted Loss Per Share of Common Stock (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2014	Aug. 31, 2013
Numerator:
(Loss) income from continuing operations	$ (9.7)	$ 197.6	$ (61.2)	$ 171.8
Income (loss) from discontinued operations, net of income taxes	0.2	(0.2)	(0.6)	(0.2)
Net (loss) income	(9.5)	197.4	(61.8)	171.6
Income allocated to participating securities	0	(3.4)	0	(3.3)
Net (loss) income for basic earnings per share	(9.5)	194.0	(61.8)	168.3
Interest on convertible subordinated debentures	0	2.0	0	6.1
Net (loss) income for diluted earnings per share	$ (9.5)	$ 196.0	$ (61.8)	$ 174.4
Denominator:
Basic weighted average shares (in shares)	56.9	59.7	58.2	59.5
Effect of:
Convertible subordinated notes (in shares)	0	22.2	0	22.2
Employee stock options (in shares)	0	0.2	0	0.2
Diluted weighted average shares (in shares)	56.9	82.1	58.2	81.9
Basic
(Loss) income per share from continuing operations (in USD per share)	$ (0.17)	$ 3.25	$ (1.05)	$ 2.83
Loss per share from discontinued operations, net of income taxes (in USD per share)	$ 0.00	$ 0.00	$ (0.01)	$ 0.00
Net (loss) income per share (in USD per share)	$ (0.17)	$ 3.25	$ (1.06)	$ 2.83
Diluted
(Loss) income per share from continuing operations (in USD per share)	$ (0.17)	$ 2.39	$ (1.05)	$ 2.13
Loss per share from discontinued operations, net of income taxes (in USD per share)	$ 0.00	$ 0.00	$ (0.01)	$ 0.00
Net (loss) income per share (in USD per share)	$ (0.17)	$ 2.39	$ (1.06)	$ 2.13