Segment Information (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2022 USD ($) Segment	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)
Segment Information [Abstract]
Number of reportable segments | Segment	2
Revenues	$ 1,744,822	$ 1,228,206	$ 1,022,970
Income from operations	217,833	148,877	78,290
Depreciation and amortization	16,296	5,411	3,249
Transaction costs	7,724	869	3,648
Change in fair value of contingent consideration	10,380	3,249	$ 6,762
Total assets	1,497,428	$ 720,614
Dealerships [Member]
Segment Information [Abstract]
Total assets	1,078,457
Distribution [Member]
Segment Information [Abstract]
Total assets	418,971
Operating Segments [Member] | Dealerships [Member]
Segment Information [Abstract]
Revenues	1,608,972
Income from operations	211,401
Depreciation and amortization	7,628
Transaction costs	5,347
Change in fair value of contingent consideration	10,189
Operating Segments [Member] | Distribution [Member]
Segment Information [Abstract]
Revenues	135,850
Income from operations	6,432
Depreciation and amortization	8,668
Transaction costs	2,377
Change in fair value of contingent consideration	$ 191