Goodwill and Intangible Assets - Summary of Changes in Goodwill and Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Goodwill [Roll Forward]
Net balance - beginning of period			$ 336,602
Acquisition			0
Net balance - end of period	$ 336,602		336,602
Finite-Lived Intangible Assets [Roll Forward]
Accumulated amortization	(2,100)	$ (2,100)	(6,438)	$ (5,700)
Net balance - end of period	49,964		49,964
Intangible Assets Disclosure [Roll Forward]
Net balance - beginning of period			205,391
Acquisition			1,004
Other adjustments			(72)
Accumulated amortization	(2,100)	(2,100)	(6,438)	(5,700)
Net balance - end of period	199,885		199,885
Trade Names
Indefinite-Lived Intangible Assets [Roll Forward]
Net balance - beginning of period			149,921
Acquisitions			0
Net balance - end of period	149,921		149,921
Developed Technologies
Finite-Lived Intangible Assets [Roll Forward]
Net balance - beginning of period			3,964
Acquisitions			0
Accumulated amortization			(404)
Net balance - end of period	3,560		3,560
Intangible Assets Disclosure [Roll Forward]
Accumulated amortization			(404)
Customer Relationships
Finite-Lived Intangible Assets [Roll Forward]
Net balance - beginning of period			46,403
Acquisitions			0
Accumulated amortization			(4,574)
Net balance - end of period	41,829		41,829
Intangible Assets Disclosure [Roll Forward]
Accumulated amortization			(4,574)
Domain Names
Finite-Lived Intangible Assets [Roll Forward]
Net balance - beginning of period			1,750
Acquisitions			0
Other adjustments			(72)
Accumulated amortization			(471)
Net balance - end of period	1,207		1,207
Intangible Assets Disclosure [Roll Forward]
Accumulated amortization			(471)
Internally Developed Software
Finite-Lived Intangible Assets [Roll Forward]
Net balance - beginning of period			3,353
Acquisitions			1,004
Accumulated amortization	(400)	(300)	(989)	(800)
Net balance - end of period	3,368		3,368
Intangible Assets Disclosure [Roll Forward]
Accumulated amortization	$ (400)	$ (300)	$ (989)	$ (800)