Segment Information (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2024 USD ($) segment	Dec. 31, 2023 USD ($)	Sep. 30, 2024 USD ($)
Segment Information [Abstract]
Number of reportable segments | segment	2
Revenue	$ 375,814	$ 364,013
Income (loss) from operations	(1,973)	6,471
Depreciation and amortization	6,037	4,905
Transaction costs	559	579
Change in fair value of contingent consideration	242	572
Restructuring and impairment	1,898	0
Total assets	1,611,546	1,693,073	$ 1,589,989
Eliminations
Segment Information [Abstract]
Revenue	(45)	(60)
Income (loss) from operations	(12)	(7)
Depreciation and amortization	0	0
Transaction costs	0	0
Change in fair value of contingent consideration	0	0
Restructuring and impairment	0	0
Total assets	(10)	(33)
Dealerships
Segment Information [Abstract]
Restructuring and impairment	1,200
Dealerships | Operating Segments
Segment Information [Abstract]
Revenue	347,670	331,607
Income (loss) from operations	3,020	6,943
Depreciation and amortization	3,489	2,902
Transaction costs	512	440
Change in fair value of contingent consideration	242	572
Restructuring and impairment	1,156	0
Total assets	1,391,436	1,445,553
Distribution
Segment Information [Abstract]
Restructuring and impairment	700
Distribution | Operating Segments
Segment Information [Abstract]
Revenue	28,189	32,466
Income (loss) from operations	(4,981)	(465)
Depreciation and amortization	2,548	2,003
Transaction costs	47	139
Change in fair value of contingent consideration	0	0
Restructuring and impairment	742	0
Total assets	$ 220,120	$ 247,553