Earnings Per Share - Summary of Weighted-Average Number of Shares used in Calculation of Basic and Diluted Earnings Per Share (Details) In Thousands, unless otherwise specified	3 Months Ended
Oct. 31, 2013	Oct. 31, 2012
Weighted-average number of shares used in the calculation of basic and diluted earnings per share
Basic weighted-average number of shares	21,038	20,807
Effect of dilutive securities:
Stock options	87
Non-vested restricted Class B common stock	1,787	1,277
Diluted weighted-average number of shares	22,912	22,084

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of non vested restricted common stock.

No definition available.

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- Definition

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of stock options.

+ References

No definition available.

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- 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

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- 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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 45

-Paragraph 10

-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1448-109256

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Weighted-Average Number of Common Shares Outstanding

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

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