Revenue and Accounts Receivable - Schedule of Rollforward of Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2025	Mar. 31, 2024
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 39,166	$ 35,406	$ 40,840	$ 37,056	$ 40,840
Current period provisions	14,391	12,797		23,015	19,547
Write-offs charged against allowance	(4,761)	(5,859)		(12,209)	(14,616)
Recoveries of amounts previously written off	545	361		1,479	1,126
Mississippi recovery of uncollectible accounts					(4,192)
Ending balance	$ 49,341	$ 42,705	$ 35,406	$ 49,341	$ 42,705