Accounting Policies (Inventories, net) (Details) - USD ($) $ in Thousands		Mar. 31, 2019	Mar. 31, 2018
Inventory, Net [Abstract]
Truck and trailer parts and accessories (a)	[1]	$ 94,344	$ 83,335
Hitches and towing components (b)	[2]	20,113	18,627
Moving supplies and propane (b)	[2]	10,356	9,370
Subtotal		124,813	111,332
Less: LIFO reserves		(18,987)	(16,126)
Less: excess and obsolete reserves		(2,322)	(5,329)
Total		$ 103,504	$ 89,877

[1] Primarily held for internal usage, including equipment manufacturing and repair

[2] Primarily held for retail sales