Earnings Per Share (Details) - USD ($)	3 Months Ended
Oct. 31, 2018	Oct. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Share repurchased during period (in shares)	0	0
Weighted average performance shares outstanding during the period that are excluded from EPS Calculation (in shares)	236,000	252,000
Numerator:
Net income (loss) for basic calculation	$ 3,468,000	$ (1,660,000)
Numerator for diluted calculation	$ 3,468,000	$ (1,660,000)
Denominator:
Denominator for basic calculation (in shares)	23,999,000	23,797,000
Effect of dilutive securities: Stock-based awards (in shares)	376,000	0
Denominator for diluted calculation (in shares)	24,375,000	23,797,000
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)	279,000	2,246,000

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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of convertible debt securities using the if-converted method.

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

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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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Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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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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