Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Sep. 30, 2021
Component of Inventory [Abstract]
Inventories, net	$ 372,959	$ 143,880
New Vessels [Member]
Component of Inventory [Abstract]
Inventories, net	243,090	105,625
Pre-owned Vessels [Member]
Component of Inventory [Abstract]
Inventories, net	51,607	22,906
Parts and Accessories, Work in Process, Net [Member]
Component of Inventory [Abstract]
Inventories, net	$ 78,262	$ 15,349