Acquisitions, Roscioli Yachting Center Acquisition (Details) $ in Thousands	Sep. 30, 2021 USD ($) Store	Dec. 31, 2020 USD ($) Location	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)
Acquisition [Abstract]
Number of stores | Store	70
Summary of Assets Acquired and Liabilities Assumed [Abstract]
Goodwill	$ 168,491		$ 113,059	$ 113,059
Roscioli Yachting Center [Member]
Acquisition [Abstract]
Number of stores | Location		1
Summary of Assets Acquired and Liabilities Assumed [Abstract]
Inventories		$ 87
Prepaid expenses		1
Property and equipment		41,300
Identifiable intangible assets		1,530
Goodwill		2,993
Accounts payable		(180)
Accrued expenses		(185)
Total purchase price		$ 45,546