Long-term Debt and Line of Credit - Summary of Long-term Debt and Line of Credit (Details) - USD ($) $ in Thousands	9 Months Ended
Jun. 30, 2023	Sep. 30, 2022
Debt Instrument [Line Items]
Total debt outstanding	$ 465,653	$ 452,355
Less current portion (net of debt issuance costs)	(23,896)	(21,642)
Less unamortized portion of debt issuance costs	(7,868)	(9,551)
Long-term debt, net of current portion and unamortized debt issuance costs	433,889	421,162
Term note payable to Truist Bank, secured and bearing interest at 7.14% at June 30, 2023 and 5.31% at September 30, 2022. The note requires quarterly principal payments commencing on December 31, 2022 and maturing with a full repayment on August 9, 2027
Debt Instrument [Line Items]
Total debt outstanding	$ 428,313	$ 445,000
Debt instrument, interest rate, stated percentage	7.14%	5.31%
Revolving note payable for an amount up to $65.0 million to Truist Bank, secured and bearing interest at 7.14% at June 30, 2023. The note requires full repayment on August 9, 2027
Debt Instrument [Line Items]
Total debt outstanding	$ 30,000	$ 0
Debt instrument, interest rate, stated percentage	7.14%
Line of credit facility, maximum borrowing capacity	$ 65,000
Notes payable to commercial vehicle lenders secured by the value of the vehicles bearing interest at rates ranging from 0.0% to 8.4% per annum. The notes require monthly installment payments of principal and interest ranging from $100 to $5,600 through July 2028
Debt Instrument [Line Items]
Total debt outstanding	$ 4,158	4,173
Notes payable to commercial vehicle lenders secured by the value of the vehicles bearing interest at rates ranging from 0.0% to 8.4% per annum. The notes require monthly installment payments of principal and interest ranging from $100 to $5,600 through July 2028 \| Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	0.00%
Debt instrument, periodic payment	$ 100
Notes payable to commercial vehicle lenders secured by the value of the vehicles bearing interest at rates ranging from 0.0% to 8.4% per annum. The notes require monthly installment payments of principal and interest ranging from $100 to $5,600 through July 2028 \| Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	8.40%
Debt instrument, periodic payment	$ 5,600
Note payable to Tom George Yacht Group, unsecured and bearing interest at 5.5% per annum. The note requires monthly interest payments, with a balloon payment of principal due on December 1, 2023
Debt Instrument [Line Items]
Total debt outstanding	$ 2,056	2,056
Debt instrument, interest rate, stated percentage	5.50%
Note payable to Norfolk Marine Company, unsecured and bearing interest at 4.0% per annum. The note requires quarterly interest payments, with a balloon payment of principal due on December 1, 2024
Debt Instrument [Line Items]
Total debt outstanding	$ 1,126	$ 1,126
Debt instrument, interest rate, stated percentage	4.00%

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Contractual interest rate for funds borrowed, under the debt agreement.

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