Equity (Schedule of Earnings per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	12 Months Ended
Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Loss from operations	$ 703	$ (1,287)	$ (5,081)	$ (1,335)	$ (14,975)	$ (10,477)	$ (4,994)	$ (5,538)	$ (7,000)	$ (35,984)	$ (17,453)
Undistributed earnings allocated to common shareholders for basic and diluted net income per share									$ (7,000)	$ (35,984)	$ (17,453)
Weighted-average number of basic and diluted shares outstanding	29,386	29,295	29,033	28,832	28,734	28,005	27,652	27,534	29,136	27,983	27,266
Dilutive options outstanding, unvested stock units, unvested stock awards and ESPP									29,136	27,983	27,266
Denominator for diluted net loss per share - adjusted weighted average shares outstanding									29,136	27,983	27,266
Net loss per basic and diluted share (in dollars per share)	$ 0.02	$ (0.04)	$ (0.18)	$ (0.05)	$ (0.52)	$ (0.37)	$ (0.18)	$ (0.20)	$ (0.24)	$ (1.29)	$ (0.64)
Weighted average antidilutive options, unvested restricted stock units and awards, unvested performance stock units and ESPP shares excluded from the computation									1,109	810	949
Average market price of common stock (in dollars per share)									$ 3.03	$ 3.91	$ 5.87

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Amount of undistributed earnings (loss) allocated to common stock as if earnings had been distributed. Excludes distributed earnings.

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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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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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

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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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Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

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