Schedule I - Condensed Financial Information of U-Haul Holding Company (Statements of Operations) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021
Revenues:
Net interest income from subs	$ 5,864,691	$ 5,739,747	$ 4,541,985
Expenses:
Operating expenses	3,024,547	2,676,541	2,187,684
Total costs and expenses	4,420,585	4,094,750	3,580,838
Equity in earnings of subsidiaries	0	0	0
Pretax earnings	1,217,923	1,475,497	796,658
Income tax expense	(294,925)	(352,211)	(185,802)
Net earnings available to common shareholders	922,998	1,123,286	610,856
U-Haul Holding Company [Member]
Revenues:
Net interest income from subs	54,823	1,516	720
Expenses:
Operating expenses	13,937	5,517	6,753
Other expenses	127	115	115
Total costs and expenses	14,064	5,632	6,868
Equity in earnings of subsidiaries	581,043	1,011,841	508,632
Interest income	413,170	131,400	135,673
Pretax earnings	1,034,972	1,139,125	638,157
Income tax expense	(111,974)	(15,839)	(27,301)
Net earnings available to common shareholders	$ 922,998	$ 1,123,286	$ 610,856
Basic and diluted earnings per common share	$ 5.54	$ 5.58	$ 2.87
Weighted average common shares outstanding: basic and diluted	176,470,092	176,470,092	176,470,092