Condensed Consolidating Financial Information - Condensed Consolidating Statements of Operations (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Nov. 30, 2013	Aug. 31, 2013	May 31, 2013	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	May 31, 2012	Feb. 29, 2012	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2011
Condensed Income Statements, Captions [Line Items]
Net sales	$ 485.3	$ 367.5	$ 286.6	$ 243.7	$ 298.2	$ 244.9	$ 249.9	$ 201.9	$ 1,383.1	$ 994.9	$ 918.1
Cost of sales (exclusive of items shown separately below)	431.0	326.7	254.4	217.5	261.3	214.1	220.3	173.9	1,229.6	869.6	799.3
Selling, general and administrative									53.6	41.9	40.9
Depreciation and amortization									43.8	22.3	24.6
Interest expense									48.7	22.3	30.8
Other, net									33.6	25.6	13.5
(Loss) income from continuing operations before income taxes	1.6	(9.0)	(9.6)	(9.2)	4.4	(0.5)	4.6	4.7	(26.2)	13.2	9.0
Income tax (benefit) provision									(193.9)	18.9	6.1
Income (loss) from continuing operations	(4.1)	197.6	(11.7)	(14.1)	(0.7)	(8.7)	1.3	2.4	167.7	(5.7)	2.9
Income from discontinued operations	0.4	(0.2)	(0.1)	0.1	3.5	(0.8)	0.4		0.2	3.1
(Loss) income before equity income of subsidiaries									167.9	(2.6)	2.9
Equity income of subsidiaries
Net income (loss)	(3.7)	197.4	(11.8)	(14.0)	2.8	(9.5)	1.7	2.4	167.9	(2.6)	2.9
Comprehensive (loss) income									431.8	(189.5)	(15.3)
Parent [Member]
Condensed Income Statements, Captions [Line Items]
Net sales
Cost of sales (exclusive of items shown separately below)
Selling, general and administrative									31.1	26.4	27.1
Depreciation and amortization									0.1	0.1	0.1
Interest expense									46.2	18.7	25.6
Other, net									32.8	26.7	11.9
(Loss) income from continuing operations before income taxes									(110.2)	(71.9)	(64.7)
Income tax (benefit) provision									(81.8)	(16.9)	(25.5)
Income (loss) from continuing operations									(28.4)	(55.0)	(39.2)
Income from discontinued operations									0.2	3.1
(Loss) income before equity income of subsidiaries									(28.2)	(51.9)	(39.2)
Equity income of subsidiaries									196.1	49.3	42.1
Net income (loss)									167.9	(2.6)	2.9
Comprehensive (loss) income									431.8	(189.5)	(15.3)
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Net sales									1,354.7	962.0	885.0
Cost of sales (exclusive of items shown separately below)									1,206.3	844.2	774.8
Selling, general and administrative									21.2	14.6	12.9
Depreciation and amortization									42.6	21.1	23.5
Interest expense									2.5	3.6	5.2
Other, net									2.8	(4.3)	(1.5)
(Loss) income from continuing operations before income taxes									79.3	82.8	70.1
Income tax (benefit) provision									(101.8)	34.4	39.8
Income (loss) from continuing operations									181.1	48.4	30.3
Income from discontinued operations
(Loss) income before equity income of subsidiaries									181.1	48.4	30.3
Equity income of subsidiaries
Net income (loss)									181.1	48.4	30.3
Comprehensive (loss) income									375.7	(119.5)	4.1
Non-guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Net sales									28.4	32.9	33.1
Cost of sales (exclusive of items shown separately below)									23.9	26.0	25.0
Selling, general and administrative									1.3	0.9	0.9
Depreciation and amortization									1.1	1.1	1.0
Interest expense
Other, net									(2.6)	2.6	2.6
(Loss) income from continuing operations before income taxes									4.7	2.3	3.6
Income tax (benefit) provision									(10.3)	1.4	(8.2)
Income (loss) from continuing operations									15.0	0.9	11.8
Income from discontinued operations
(Loss) income before equity income of subsidiaries									15.0	0.9	11.8
Equity income of subsidiaries
Net income (loss)									15.0	0.9	11.8
Comprehensive (loss) income									15.0	0.9	11.8
Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Net sales
Cost of sales (exclusive of items shown separately below)									(0.6)	(0.6)	(0.5)
Selling, general and administrative
Depreciation and amortization
Interest expense
Other, net									0.6	0.6	0.5
(Loss) income from continuing operations before income taxes
Income tax (benefit) provision
Income (loss) from continuing operations
Income from discontinued operations
(Loss) income before equity income of subsidiaries
Equity income of subsidiaries									(196.1)	(49.3)	(42.1)
Net income (loss)									(196.1)	(49.3)	(42.1)
Comprehensive (loss) income									$ (390.7)	$ 118.6	$ (15.9)