Stock Award Plans - Other Stock Option Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Share-Based Payment Arrangement [Abstract]
Compensation cost for stock options	$ 1,875	$ 1,296	$ 1,676
Weighted average grant date fair value per stock option (in dollars per share)	$ 5.91	$ 5.10	$ 4.39
Total intrinsic value of options exercised	$ 214	$ 433	$ 276
Grant date fair value of options exercised	198	345	78
Cash received from option exercises	$ 1,089	$ 1,823	$ 339

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount of cash inflow from exercise of option under share-based payment arrangement.

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-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (a)
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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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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
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-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

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