Goodwill and Intangible Assets - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025	Sep. 30, 2025
Indefinite-Lived Intangible Assets [Line Items]
Impairment of intangible assets			$ 5,800
Amortization of intangible assets	$ 600	$ 2,100	$ 1,107	$ 4,300
Weighted average useful life			1 year 9 months 18 days
Goodwill	258,954		$ 258,954		$ 258,954
Internally Developed Software
Indefinite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 400	$ 300	$ 817	$ 600