Computation of Basic and Diluted Earnings Per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Feb. 28, 2013	Feb. 29, 2012
Numerator:
Net income	$ 13,513	$ 17,139
Denominator:
Weighted average shares outstanding	46,423,324	46,391,006
Weighted Average Number Diluted Shares Outstanding Adjustment	13,019	4,906
Diluted weighted average shares outstanding	46,436,343	46,395,912
Basic and diluted earnings per share	$ 0.29	$ 0.37
Anti-dilutive shares excluded in the computation of diluted earnings per share	224,252	243,960

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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+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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

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-Name Regulation S-X (SX)

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-Section 03

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-Glossary Other Comprehensive Income

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-Glossary Net Income

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

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-Appendix A

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+ Details

- Definition

The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.

+ References+ 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

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

+ Details