Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended	6 Months Ended
Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2017	Jan. 31, 2016
Weighted-average number of shares used in the calculation of basic and diluted earnings per share
Basic weighted-average number of shares	22,768	22,799	22,740	22,867
Effect of dilutive securities:
Stock options	77		58
Non-vested restricted Class B common stock	118		133	17
Diluted weighted-average number of shares	22,963	22,799	22,931	22,884

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of call options and warrants using the treasury stock method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 23
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=64863997&loc=d3e1757-109256

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Treasury Stock Method
-URI http://asc.fasb.org/extlink&oid=6527216

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Call Option
-URI http://asc.fasb.org/extlink&oid=6506649

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
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Nonvested equity-based payment awards that contain forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) that result in incremental common shares.

+ References

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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.

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