Accounts Receivable (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2024	Sep. 30, 2023
Receivables [Abstract]
Finance contracts maximum funding period	30 days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	$ 110,765	$ 113,878
Less – allowance for credit losses	(623)	(703)
Total accounts receivable, net	110,142	113,175
Contracts in transit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	48,517	25,425
Trade accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	34,862	32,065
Income tax receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	16,534	0
Manufacturer receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	10,852	11,288
Receivable for proceeds on the disposition of a business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	$ 0	$ 45,100