Long-term Debt and Line of Credit (Details) - USD ($) $ in Thousands	6 Months Ended
Mar. 31, 2021	Sep. 30, 2020
Long-term Debt and Line of Credit [Abstract]
Long-term debt, gross	$ 121,538	$ 91,536
Less current portion	(13,995)	(7,419)
Less unamortized portion of debt issuance costs	(2,464)	(2,140)
Long-term debt, net of current portion of unamortized debt issuance costs	$ 105,079	$ 81,977
Term Note Payable to Truist Bank, Secured and Bearing Interest at 2.75% at March 31, 2021 and 3.0% September 30, 2020. The Note Requires Quarterly Principal Payments Commencing on March 31, 2021 and Maturing With a Full Repayment On July 22, 2025 [Member]
Long-term Debt and Line of Credit [Abstract]
Interest rate	2.75%	3.00%
Maturity date	Jul. 22, 2025
Long-term debt, gross	$ 108,625	$ 80,000
Revolving Note Payable For an Amount up to $30.0 Million to Truist Bank [Member]
Long-term Debt and Line of Credit [Abstract]
Line of credit maximum borrowing capacity	30,000
Long-term debt, gross	$ 0	0
Note Payable to Commercial Vehicle Lenders Secured by the Value of the Vehicles Bearing Interest at Rates Ranging From 0.0% to 8.9% Per Annum. The Note Requires Monthly Installment Payments of Principal and Interest Ranging from $100 to $5,600 Through March 2027 [Member]
Long-term Debt and Line of Credit [Abstract]
Maturity date	Mar. 31, 2027
Frequency of periodic payment	Monthly
Long-term debt, gross	$ 3,275	2,454
Note Payable to Commercial Vehicle Lenders Secured by the Value of the Vehicles Bearing Interest at Rates Ranging From 0.0% to 8.9% Per Annum. The Note Requires Monthly Installment Payments of Principal and Interest Ranging from $100 to $5,600 Through March 2027 [Member] \| Minimum [Member]
Long-term Debt and Line of Credit [Abstract]
Interest rate	0.00%
Monthly installment payment amount	$ 100
Note Payable to Commercial Vehicle Lenders Secured by the Value of the Vehicles Bearing Interest at Rates Ranging From 0.0% to 8.9% Per Annum. The Note Requires Monthly Installment Payments of Principal and Interest Ranging from $100 to $5,600 Through March 2027 [Member] \| Maximum [Member]
Long-term Debt and Line of Credit [Abstract]
Interest rate	8.90%
Monthly installment payment amount	$ 5,600
Note Payable to Central Marine Services, Inc., Unsecured and Bearing Interest at 5.5% Per Annum. The Note Requires Monthly Interest Payments, with a Balloon Payment of Principal Due On February 1, 2022 [Member]
Long-term Debt and Line of Credit [Abstract]
Interest rate	5.50%
Maturity date	Feb. 01, 2022
Long-term debt, gross	$ 2,164	2,164
Note Payable To Tom George Yacht Sales, Inc., Unsecured and Bearing Interest At 5.5% Per Annum. The Note Requires Quarterly Interest Payments, With a Balloon Payment of Principal Due On December 1, 2023 [Member]
Long-term Debt and Line of Credit [Abstract]
Interest rate	5.50%
Maturity date	Dec. 01, 2023
Long-term debt, gross	$ 2,056	0
Note Payable to Ocean Blue Yacht Sales, Unsecured and Bearing Interest at 5.0% Per Annum. The Note Requires Quarterly Interest Payments, with a Balloon Payment of Principal Due on February 1, 2022 [Member]
Long-term Debt and Line of Credit [Abstract]
Interest rate	5.00%
Maturity date	Feb. 01, 2022
Long-term debt, gross	$ 1,920	1,920
Note Payable to Slalom Shop, LLC, Unsecured and Bearing Interest at 5.0% Per Annum. The Note Requires Quarterly Interest Payments, with a Balloon Payment of Principal Due on December 1, 2021 [Member]
Long-term Debt and Line of Credit [Abstract]
Interest rate	5.00%
Maturity date	Dec. 01, 2021
Long-term debt, gross	$ 1,271	1,271
Note Payable to Bosun's Marine, Inc., Unsecured and Bearing Interest at 4.5% Per Annum. The Note Requires Annual Interest Payments with a Balloon Payment Due on June 1, 2021 [Member]
Long-term Debt and Line of Credit [Abstract]
Interest rate	4.50%
Maturity date	Jun. 01, 2021
Long-term debt, gross	$ 1,227	1,227
Note Payable to Rebo, Inc., Unsecured and Bearing Interest at 5.5% Per Annum. The note Requires Annual Interest Payments with a Balloon Payment Due on April 1, 2021 [Member]
Long-term Debt and Line of Credit [Abstract]
Interest rate	5.50%
Maturity date	Apr. 01, 2021
Long-term debt, gross	$ 1,000	1,000
Note Payable to Lab Marine, Inc., Unsecured and Bearing Interest at 6.0% Per Annum. The Note was Repaid Full [Member]
Long-term Debt and Line of Credit [Abstract]
Interest rate	6.00%
Long-term debt, gross	$ 0	$ 1,500

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.

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-Publisher FASB
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