Income Per Share Weighted average shares outstanding (Details) In Millions, unless otherwise specified	3 Months Ended
Feb. 28, 2013	Feb. 29, 2012
Weighted Average Shares Outstanding [Abstract]
Weighted-average common shares outstanding	46.0	44.7
Weighted-average participating shares outstanding	0.1	1.2
Weighted Average Number of Shares Outstanding, Including Participating Shares, Basic	46.1	45.9
Weighted-average common shares outstanding - assuming dilution	46.7	46.0
Options to purchase common stock and restricted shares that were excluded from computation of diluted earnings per share because they were anti-dilutive	0.1	1.1

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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+ Details

- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References+ Details

- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

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

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-Glossary Weighted-Average Number of Common Shares Outstanding

-URI http://asc.fasb.org/extlink&oid=6528421

+ Details