Goodwill Other Intangible Assets and Other Long Term Assets - Additional Information (Detail) $ in Thousands	1 Months Ended				12 Months Ended
	Nov. 30, 2021 USD ($)	Jul. 31, 2021 USD ($)	May 31, 2021 USD ($)	Oct. 31, 2020 USD ($)	Sep. 30, 2022 USD ($) Segment	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)
Schedule Of Goodwill And Other Assets [Line Items]
Accounts receivable, net					$ 50,287	$ 47,651
Inventories					454,359	230,984
Short-term borrowings					132,026	23,943
Accrued expenses					89,402	86,594
Accounts payable					34,342	25,739
Customer deposits					144,427	100,660
Goodwill					235,585	195,563	$ 84,240
Other identifiable intangibles					10,886	5,559
Revenue					2,308,098	2,063,257	1,509,713
Estimated income before taxes					261,921	205,794	$ 97,440
Other intangible assets, net					10,886	5,559
Goodwill and other intangible assets increased from acquisitions					45,300	116,800
Business acquisition, goodwill for tax purposes					$ 10,500	110,800
Number of reportable segments | Segment					2
Other long-term assets					$ 9,455	$ 8,818
Nisswa Marine, Inc [Member]
Schedule Of Goodwill And Other Assets [Line Items]
Aggregate purchase price		$ 15,300
Cruisers Yachts [Member]
Schedule Of Goodwill And Other Assets [Line Items]
Aggregate purchase price			$ 62,700
Accounts receivable, net			3,100
Inventories			26,200
Short-term borrowings			11,700
Accrued expenses			10,300
Accounts payable			3,000
Goodwill			40,134
Intangible assets			4,602
Cash acquired			$ 5,993
Cruisers Yachts [Member] | Customer Relationships [Member]
Schedule Of Goodwill And Other Assets [Line Items]
Weighted average useful life			2 years
SkipperBuds [Member]
Schedule Of Goodwill And Other Assets [Line Items]
Aggregate purchase price				$ 55,000
Accounts receivable, net				5,400
Inventories				42,300
Short-term borrowings				30,500
Accrued expenses				$ 14,600
Weighted average useful life				3 years 3 months 18 days
Maximum amount of consideration paid under earnout				$ 9,300
Fair value of contingent consideration				8,200
Customer deposits				7,500
Goodwill				56,363
Other identifiable intangibles				2,000
Revenue					302,600
Estimated income before taxes					$ 31,300
Other intangible assets, net				2,000
Estimated contingent consideration				8,200
Intangible assets				1,978
Cash acquired				30,615
Aggregate consideration				$ 58,461
Intrepid And Texas Master Craft [Member]
Schedule Of Goodwill And Other Assets [Line Items]
Tangible assets acquired	$ 20,300
Goodwill	39,600
Estimated contingent consideration	6,000
Intangible assets	7,300
Cash acquired	9,400
Aggregate consideration	67,200
Texas Master Craft [Member]
Schedule Of Goodwill And Other Assets [Line Items]
Goodwill	$ 10,700