The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Reference 2: http://www.xbrl.org/2003/role/exampleRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Goodwill and Intangible Assets - (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Indefinite and Finite Lived Intangible Assets by Major Class
Amortization expense	$ 3.2	$ 3.4	$ 4.1
Minimum
Indefinite and Finite Lived Intangible Assets by Major Class
Definite-lived intangible assets, useful life	3 years
Maximum
Indefinite and Finite Lived Intangible Assets by Major Class
Definite-lived intangible assets, useful life	10 years