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Acquisition - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jul. 06, 2017	Jun. 30, 2018	Sep. 30, 2018
Business Acquisition [Line Items]
Goodwill		$ 32,230	$ 32,061
Cobalt Boats, LLC
Business Acquisition [Line Items]
Fair value of total consideration transferred	$ 130,525
Cash consideration paid	129,525
Equity consideration paid	$ 1,000
Business acquisition, share price (in dollars per share)	$ 25.47
Acquired finite-lived intangible assets, weighted average useful life	19 years 9 months 18 days
Goodwill	$ 19,791
Acquisition related costs		$ 3,056
Common Stock \| Cobalt Boats, LLC \| Class A Common Stock
Business Acquisition [Line Items]
Issuance of Class A common stock for offerings, net of underwriting discounts (in shares)	39,262
Dealer relationships
Business Acquisition [Line Items]
Useful Life (in years)	20 years
Dealer relationships \| Cobalt Boats, LLC
Business Acquisition [Line Items]
Useful Life (in years)	20 years
Patent
Business Acquisition [Line Items]
Useful Life (in years)	15 years
Patent \| Cobalt Boats, LLC
Business Acquisition [Line Items]
Useful Life (in years)	15 years