Valuation and Qualifying Accounts (Details) - Credit Losses - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Movement in valuation and qualifying accounts
Balance at Beginning of Period	$ 428	$ 553	$ 545
Charges (credits) to Expense	286	171	74
Deductions	(255)	(296)	(66)
Balance at End of Period	$ 459	$ 428	$ 553