Earnings Per Share (Details) - USD ($)	3 Months Ended	9 Months Ended
Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Share repurchased during period (in shares)	0	0	0	0
Weighted average performance shares outstanding during the period that are excluded from EPS Calculation (in shares)	203,000	246,000	201,000	242,000
Numerator:
Net (loss) income for basic calculation	$ (3,989,000)	$ 7,612,000	$ 5,894,000	$ 18,906,000
Numerator for diluted calculation	$ (3,989,000)	$ 7,612,000	$ 5,894,000	$ 18,906,000
Denominator:
Denominator for basic calculation (in shares)	24,982,000	24,192,000	24,730,000	24,074,000
Effect of dilutive securities: Stock-based awards (in shares)	0	138,000	162,000	189,000
Denominator for diluted calculation (in shares)	24,982,000	24,330,000	24,892,000	24,263,000
Stock options, performance shares (with the performance conditions satisfied), RSUs and restricted stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive equity-classified stock-based awards not included in calculation of diluted earnings per share (in shares)	1,440,000	1,674,000	642,000	1,103,000

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Weighted average number of RSUs with performance measures (which we refer to as performance shares) outstanding during the period, which are excluded from calculation of basic and diluted earnings per share as the respective performance conditions have not yet been satisfied.

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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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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities, and addition from assumption of issuance of common shares for dilutive potential common shares; of income (loss) available to common shareholders.

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