Condensed Consolidating Financial Information - Condensed Consolidating Statements of Operations and Comprehensive Income (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
Condensed Income Statements, Captions [Line Items]
Net sales	$ 419.5	$ 367.5	$ 1,152.3	$ 897.8
Cost of sales (exclusive of items shown separately below)	374.2	326.7	1,027.2	798.6
Selling, general and administrative	9.7	14.1	28.1	39.9
Depreciation and amortization	15.7	15.2	45.9	26.6
Interest expense	14.0	12.4	39.0	36.2
Other, net	16.3	8.1	72.2	24.3
(Loss) income from continuing operations before income taxes	(10.4)	(9.0)	(60.1)	(27.8)
Income tax (benefit) provision	(0.7)	(206.6)	1.1	(199.6)
(Loss) income from continuing operations	(9.7)	197.6	(61.2)	171.8
(Loss) income from discontinued operations	0.2	(0.2)	(0.6)	(0.2)
(Loss) income before equity income of subsidiaries	(9.5)	197.4	(61.8)	171.6
Equity income of subsidiaries	0	0	0	0
Net (loss) income	(9.5)	197.4	(61.8)	171.6
Comprehensive (loss) income	(2.0)	220.4	(39.1)	240.4
Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Net sales	0	0	0	0
Cost of sales (exclusive of items shown separately below)	(0.1)	(0.2)	(0.4)	(0.5)
Selling, general and administrative	0	0	0	0
Depreciation and amortization	0	0	0	0
Interest expense	0	0	0	0
Other, net	0.1	0.2	0.4	0.5
(Loss) income from continuing operations before income taxes	0	0	0	0
Income tax (benefit) provision	0	0	0	0
(Loss) income from continuing operations	0	0	0	0
(Loss) income from discontinued operations	0	0	0	0
(Loss) income before equity income of subsidiaries	0	0	0	0
Equity income of subsidiaries	(10.8)	(157.1)	(28.3)	(181.1)
Net (loss) income	(10.8)	(157.1)	(28.3)	(181.1)
Comprehensive (loss) income	(16.0)	(173.3)	(43.8)	(229.7)
Parent [Member]
Condensed Income Statements, Captions [Line Items]
Net sales	0	0	0	0
Cost of sales (exclusive of items shown separately below)	0	0	0	0
Selling, general and administrative	3.4	6.6	9.0	23.2
Depreciation and amortization	0	0.1	0.1	0.1
Interest expense	13.5	11.8	37.1	34.4
Other, net	9.8	4.2	59.3	26.9
(Loss) income from continuing operations before income taxes	(26.7)	(22.7)	(105.5)	(84.6)
Income tax (benefit) provision	(6.2)	(63.2)	(16.0)	(75.3)
(Loss) income from continuing operations	(20.5)	40.5	(89.5)	(9.3)
(Loss) income from discontinued operations	0.2	(0.2)	(0.6)	(0.2)
(Loss) income before equity income of subsidiaries	(20.3)	40.3	(90.1)	(9.5)
Equity income of subsidiaries	10.8	157.1	28.3	181.1
Net (loss) income	(9.5)	197.4	(61.8)	171.6
Comprehensive (loss) income	(2.0)	220.4	(39.1)	240.4
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Net sales	413.7	361.4	1,133.1	878.8
Cost of sales (exclusive of items shown separately below)	369.4	322.3	1,009.8	784.5
Selling, general and administrative	5.9	7.1	17.9	15.9
Depreciation and amortization	15.4	14.8	45.0	25.7
Interest expense	0.5	0.6	1.9	1.8
Other, net	7.2	2.9	14.4	(5.4)
(Loss) income from continuing operations before income taxes	15.3	13.7	44.1	56.3
Income tax (benefit) provision	4.7	(136.9)	16.2	(116.1)
(Loss) income from continuing operations	10.6	150.6	27.9	172.4
(Loss) income from discontinued operations	0	0	0	0
(Loss) income before equity income of subsidiaries	10.6	150.6	27.9	172.4
Equity income of subsidiaries	0	0	0	0
Net (loss) income	10.6	150.6	27.9	172.4
Comprehensive (loss) income	15.8	166.8	43.4	221.0
Non-guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Net sales	5.8	6.1	19.2	19.0
Cost of sales (exclusive of items shown separately below)	4.9	4.6	17.8	14.6
Selling, general and administrative	0.4	0.4	1.2	0.8
Depreciation and amortization	0.3	0.3	0.8	0.8
Interest expense	0	0	0	0
Other, net	(0.8)	0.8	(1.9)	2.3
(Loss) income from continuing operations before income taxes	1.0	0	1.3	0.5
Income tax (benefit) provision	0.8	(6.5)	0.9	(8.2)
(Loss) income from continuing operations	0.2	6.5	0.4	8.7
(Loss) income from discontinued operations	0	0	0	0
(Loss) income before equity income of subsidiaries	0.2	6.5	0.4	8.7
Equity income of subsidiaries	0	0	0	0
Net (loss) income	0.2	6.5	0.4	8.7
Comprehensive (loss) income	$ 0.2	$ 6.5	$ 0.4	$ 8.7