Related Party Transactions (Narratives) (Details) - USD ($)	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Sac Holdings [Member]
Related party notes receivable:
Cash interest payments	$ 400,000
Related party costs and expenses:
Interest paid (received) in cash on derivative contracts	400,000
Sac Holdings, Four Sac, Five Sac, Galaxy, Privite mini [Member]
Related party costs and expenses:
Revenue, excluding dealer agreement commissions and expenses	29,700,000	$ 29,800,000	$ 28,500,000
Expenses, related parties	2,400,000	2,400,000	2,400,000
Cash flow, related party	27,300,000	27,400,000	25,900,000
Revenue, generated by the dealer agreement from related parties	384,500,000	418,900,000	417,900,000
Commission expenses, generated from dealer agreement with related parties	82,100,000	88,100,000	88,300,000
Various Subsidiaries of Amerco [Member]
Related party notes receivable:
One time cash interest proceeds	2,900,000
Amerco, Uhaul Intl [Member]
Related party notes receivable:
One time cash interest proceeds	8,900
Notes receivable, related party	$ 37,200,000	$ 37,000,000	$ 38,500,000
Amerco, Uhaul Intl [Member] | Minimum [Member]
Property Management Fee [Abstract]
Management fee rate	4.00%
Amerco, Uhaul Intl [Member] | Maximum [Member]
Property Management Fee [Abstract]
Management fee rate	10.00%