Leases (Components of our right-of-use assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Mar. 31, 2021
Finance Lease [Abstract]
Buildings and Improvements	$ 136,213	$ 132,901
Furniture and equipment	14,732	22,316
Rental trailers and other rental equipment	173,940	203,594
Rental trucks	1,243,830	1,494,098
Right-of-use assets, gross	1,568,715	1,852,909
Less: Accumulated depreciation	(796,451)	(883,366)
Right of use assets, net	772,264	969,543
Finance Lease [Member]
Finance Lease [Abstract]
Buildings and Improvements	0	0
Furniture and equipment	14,732	22,316
Rental trailers and other rental equipment	173,940	203,594
Rental trucks	1,243,830	1,494,098
Right-of-use assets, gross	1,432,502	1,720,008
Less: Accumulated depreciation	(739,688)	(842,970)
Right of use assets, net	692,814	877,038
Operating Lease [Member]
Finance Lease [Abstract]
Buildings and Improvements	136,213	132,901
Furniture and equipment	0	0
Rental trailers and other rental equipment	0	0
Rental trucks	0	0
Right-of-use assets, gross	136,213	132,901
Less: Accumulated depreciation	(56,763)	(40,396)
Right of use assets, net	$ 79,450	$ 92,505