Goodwill and Intangible Assets - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Sep. 30, 2023
Indefinite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 1,579	$ 3,300
Weighted average useful life	3 years 9 months 18 days
Goodwill	$ 336,602		$ 336,602
Dealerships
Indefinite-Lived Intangible Assets [Line Items]
Goodwill	295,300		295,300
Distribution
Indefinite-Lived Intangible Assets [Line Items]
Goodwill	$ 41,300		$ 41,300