Revenue from Contracts with Customers - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for doubtful accounts, beginning balance	$ 6,454	$ 4,978
Add: expense	1,485	1,675	$ 1,475
Less: write-offs (net of recoveries)	25	(199)
Allowance for doubtful accounts, ending balance	$ 7,964	$ 6,454	$ 4,978