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Basis of Presentation - Additional Information (Detail) | 9 Months Ended
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Jun. 30, 2019 Dealer Operations
Organization Consolidation And Presentation Of Financial Statements [Abstract] |
Previously independent recreational boat dealers | Dealer | 5
Recreational boat dealers | Dealer | 29
Boat brokerage operations | Operations | 2
Full-service yacht repair operations | Operations | 2

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