Stock-Based Compensation - Share-based Payment Arrangement, Option, Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
Mar. 31, 2021
Wtd. Avg. Ex. Price
Outstanding, weighted average exercise price (in dollars per share)	$ 1.55
Exercised (in dollars per share)	1.81
Outstanding, weighted average exercise price (in dollars per share)	1.29
Exercisable, weighted average exercise price (in dollars per share)	$ 1.30
Shares
Outstanding, beginning balance (in shares)	100,000
Stock options, exercised (in shares)	(49,000)
Outstanding, ending balance (in shares)	51,000
Exercisable (in shares)	34,334
Aggregate Intrinsic Value
Outstanding beginning balance	$ 37
Exercised	49
Outstanding ending balance	67
Exercisable, aggregate intrinsic value	$ 45

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Number of share options (or share units) exercised during the current period.

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