Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Sep. 30, 2025
Related Party Transaction [Line Items]
Total revenues	$ 530,711	$ 552,864	$ 1,353,565	$ 1,412,199
Accounts receivable, net	64,492		64,492		$ 60,885
Accounts payable	37,061		37,061		43,758
Tax receivable agreement liability	37,500		37,500		37,500
Affiliated Entities and Individuals
Related Party Transaction [Line Items]
Total revenues	100	500	900	3,300
Affiliated Entity
Related Party Transaction [Line Items]
Purchase of inventories	35,900	$ 28,400	112,300	118,800
Expenses incurred	800		2,400	$ 2,800
Accounts receivable, net	100		100		0
Accounts payable	5,400		5,400		4,900
Tax receivable agreement liability	$ 33,500		$ 33,500		$ 33,500