Goodwill and Intangible Assets - Summary of Changes in Goodwill and Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025
Goodwill [Roll Forward]
Net balance - beginning of period			$ 258,954
Net balance - end of period	$ 258,954		258,954
Indefinite-Lived Intangible Assets [Roll Forward]
Disposals as part of sales during the six months ended March 31, 2026			(1,100)
Impairment of intangible assets			5,800
Goodwill, Impairment Loss			0
Finite-Lived Intangible Assets [Roll Forward]
Accumulated amortization	(600)	$ (2,100)	(1,107)	$ (4,300)
Net balance - end of period	3,394		3,394
Intangible Assets Disclosure [Roll Forward]
Net balance - beginning of period			130,198
Acquisition			311
Accumulated amortization	(600)	(2,100)	(1,107)	(4,300)
Net balance - end of period	122,502		122,502
Trade Names
Indefinite-Lived Intangible Assets [Roll Forward]
Net balance - beginning of period			126,008
Disposals as part of sales during the six months ended March 31, 2026			(1,100)
Net balance - end of period	119,108		119,108
Impairment of Intangible Assets, Indefinite-Lived (Excluding Goodwill)			(5,800)
Domain Names
Indefinite-Lived Intangible Assets [Roll Forward]
Impairment of Intangible Assets, Finite-Lived			0
Finite-Lived Intangible Assets [Roll Forward]
Net balance - beginning of period			1,014
Accumulated amortization			(290)
Net balance - end of period	724		724
Intangible Assets Disclosure [Roll Forward]
Accumulated amortization			(290)
Internally Developed Software
Indefinite-Lived Intangible Assets [Roll Forward]
Impairment of Intangible Assets, Finite-Lived			0
Finite-Lived Intangible Assets [Roll Forward]
Net balance - beginning of period			3,176
Acquisitions			311
Accumulated amortization	(400)	(300)	(817)	(600)
Net balance - end of period	2,670		2,670
Intangible Assets Disclosure [Roll Forward]
Accumulated amortization	$ (400)	$ (300)	$ (817)	$ (600)