Contingencies - Warranty (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 13,926	$ 12,931	$ 13,052
Warranty provision	9,672	13,093	11,827
Warranty expenditures	(10,552)	(12,098)	(11,948)
Balance at end of period	$ 13,046	$ 13,926	$ 12,931