Income Taxes - Reconciliation Between U.S. Federal Statutory Tax Rate and Effective Tax Rate (Details)		12 Months Ended
		Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021
Reconciliation Between U.S. Federal Statutory Tax Rate and Effective Tax Rate
Provision for income taxes at U.S. federal statutory tax rate		21.00%	21.00%	21.00%
State and local taxes (net of federal tax benefit)		4.20%	3.70%	3.90%
Changes in unrecognized tax benefits		1.30%	0.00%	0.00%
Federal tax credits	[1]	(1.00%)	(1.00%)	(0.50%)
Other, net		(0.30%)	0.00%	(0.50%)
Effective tax rate		25.20%	23.70%	23.90%

[1] The amounts in Federal tax credits include tax benefits from foreign tax credits, plug-in vehicle credits, and research and development credits for fiscal 2023, 2022, and 2021. The amounts in Federal tax credits also include credits for qualified commercial clean vehicles for fiscal 2023 and alternative fuel vehicle credits for fiscal 2022 and 2021.