Balance Sheet Accounts and Supplemental Disclosures - Schedule of Other Noncurrent Assets, Net (Detail) (USD $) In Millions, unless otherwise specified	May 31, 2013	Nov. 30, 2012	Nov. 30, 2011
Other Noncurrent Assets [Line Items]
Deferred financing costs	$ 19.8	$ 7.0	$ 8.4
Recoverable from the U.S. government for conditional asset retirement obligations	14.6	13.8	12.3
Grantor trust	11.8	12.1	13.3
Other	16.3	18.2	23.7
Other noncurrent assets, net	$ 62.5	$ 51.1	$ 57.7

For an unclassified balance sheet, the carrying amount (net of accumulated amortization) as of the balance sheet date of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) that will be charged against earnings over the life of the debt instruments to which such costs pertain.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28555-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 17

-Article 5

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Namespace Prefix:	us-gaap_
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Balance Type:	debit
Period Type:	instant