Related Party Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Related Party Transaction [Line Items]
Total revenues	$ 1,872,334	$ 1,772,630	$ 1,936,310
Accounts receivable, net	60,885	73,269
Accounts payable	43,758	32,106
Tax receivable agreement liability	37,500	40,600
Affiliated Entity
Related Party Transaction [Line Items]
Purchase of inventories	136,600	124,400	94,300
Related party expenses incurred	3,600	2,500	2,100
Accounts payable	4,900	6,000
Tax receivable agreement liability	33,500	36,200
Affiliated Entities and Individuals
Related Party Transaction [Line Items]
Total revenues	3,500	4,000	1,100
Costs and expenses, related party	200	100	100
Tax receivable agreement, payments	$ 2,400	$ 2,400	$ 2,200