Revenue from Contracts with Customer - Contract Balances, Deferred Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Change In Contract With Customer Liability [Roll Forward]
Deferred revenues, beginning balance	$ 160,209	$ 143,235
Revenue recognized that was included in the deferred revenues balance at the beginning of the period	(151,859)	(133,554)
Increases due to billings, excluding amounts recognized as revenue during the period	180,888	150,528
Deferred revenues, ending balance	189,238	160,209
Deferred revenue, current portion	187,400	156,900
Deferred revenue, long-term portion	$ 1,800	$ 3,300