Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Sep. 30, 2022
Component of Inventory [Abstract]
Inventories, net	$ 527,023	$ 372,959
New Vessels [Member]
Component of Inventory [Abstract]
Inventories, net	388,004	243,090
Pre-owned Vessels [Member]
Component of Inventory [Abstract]
Inventories, net	61,658	51,607
Work in Process, Parts and Accessories [Member]
Component of Inventory [Abstract]
Inventories, net	$ 77,361	$ 78,262