Schedule V - U-Haul Holding Company and Consolidated Subsidiaries, Supplemental Information (for Property-Casualty Insurance Operations) (Details) - Property Casualty Insurance Operations [Member] - U-Haul Holding Company [Member] - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Supplemental Information For Property And Casualty Insurance Underwriters [Abstract]
Reserves for unpaid claims and claims adjustment expense	$ 131,192	$ 151,874	$ 159,162
Unearned premiums	158	97	334
Net earned premiums (1)	97,927	96,242	89,667
Net investment income (2)	25,158	7,314	24,385
Claim and claim adjustment expenses incurred related to current year	25,396	27,570	28,980
Prior years	(13,153)	(5,828)	(6,290)
Paid claims and claim adjustment expense	27,783	22,965	24,012
Net premiums written (1)	$ 98,085	$ 96,145	$ 90,002