v3.25.2
Revenue Recognition - Summary of Revenue Disaggregated Into Categories Depict the Nature, Amount, Timing, and Uncertainty of Revenue and Cash Flows Affected by Economic Factor (Details) - Sales [Member] - Product Concentration Risk [Member]
 3 Months Ended 9 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 100.00% 100.00% 100.00% 100.00%
Retail Operations [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 100.00% 100.00% 100.00% 100.00%
Product Manufacturing [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 100.00% 100.00% 100.00% 100.00%
New Boat Sales [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 63.60% 69.90% 62.70% 67.40%
New Boat Sales [Member] | Retail Operations [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 63.20% 69.50% 62.30% 67.20%
New Boat Sales [Member] | Product Manufacturing [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 98.40% 98.40% 98.70% 98.70%
Used Boat Sales [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 12.20% 8.90% 12.50% 9.40%
Used Boat Sales [Member] | Retail Operations [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 12.20% 9.00% 12.60% 9.50%
Maintenance and Repair Services [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 5.10% 4.10% 5.00% 4.60%
Maintenance and Repair Services [Member] | Retail Operations [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 5.20% 4.20% 5.00% 4.70%
Storage and Charter Rentals [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 6.40% 5.60% 7.50% 6.90%
Storage and Charter Rentals [Member] | Retail Operations [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 6.70% 5.70% 7.80% 6.90%
Finance and Insurance Products [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 3.60% 3.00% 3.40% 2.90%
Finance and Insurance Products [Member] | Retail Operations [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 3.60% 3.00% 3.40% 2.90%
Parts and Accessories [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 4.60% 4.00% 4.60% 4.50%
Parts and Accessories [Member] | Retail Operations [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 4.60% 4.00% 4.60% 4.50%
Parts and Accessories [Member] | Product Manufacturing [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 1.60% 1.60% 1.30% 1.30%
Brokerage Sales [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 4.50% 4.50% 4.30% 4.30%
Brokerage Sales [Member] | Retail Operations [Member]        
Product Information [Line Items]        
Sales Revenue Goods And Services Net Percentage 4.50% 4.60% 4.30% 4.30%