Stock-based Compensation - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
Jun. 30, 2021	Sep. 30, 2020
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs related to non-vested stock options award	$ 100	$ 100
Weighted average period to recognize remaining cost	8 months 4 days
Time-Based Restricted Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Performance-Based Restricted Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Nonvested Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period to recognize remaining cost	1 year 6 months 10 days
Unrecognized compensation costs related to non-vested stock awards	$ 9,200	$ 9,000

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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