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, 2024	Mar. 31, 2023	Mar. 31, 2022
Revenues:
Net interest income and other revenues	$ 5,625,674	$ 5,864,691	$ 5,739,747
Expenses:
Total costs and expenses	4,647,885	4,419,111	4,093,674
Total pretax earnings	840,177	1,219,397	1,476,573
Income tax expense	(211,470)	(294,925)	(352,211)
Earnings available to common stockholders	$ 628,707	924,472	1,124,362
Basic earnings per common share	$ 3.04
Diluted earnings per common share	$ 3.04
Nonvoting Common Stock [Member]
Expenses:
Earnings available to common stockholders	$ 0	$ 0	$ 0
Basic earnings per common share	$ 3.22	$ 4.62	$ 5.58
Diluted earnings per common share	$ 3.22	$ 4.62	$ 5.58
Weighted average common shares outstanding: basic	176,470,092	176,470,092	176,470,092
Weighted average common shares outstanding: diluted	176,470,092	176,470,092	176,470,092
Common stocks [Member]
Expenses:
Earnings available to common stockholders	$ 0	$ 0	$ 0
Basic earnings per common share	$ 3.04	$ 5.54	$ 7.08
Diluted earnings per common share		$ 5.54	$ 7.08
Weighted average common shares outstanding: basic	19,607,788	19,607,788	19,607,788
Weighted average common shares outstanding: diluted	19,607,788	19,607,788	19,607,788
Common stocks [Member] | Nonvoting Common Stock [Member]
Expenses:
Weighted average common shares outstanding: basic	196,077,880	196,077,880	196,077,880
U-Haul Holding Company [Member]
Revenues:
Net interest income and other revenues	$ 105,624	$ 54,823	$ 1,516
Expenses:
Operating expenses	12,834	13,937	5,517
Other expenses	125	127	115
Total costs and expenses	12,959	14,064	5,632
Equity in earnings of subsidiaries	160,302	582,517	1,012,917
Interest income	519,070	413,170	131,400
Total pretax earnings	772,037	1,036,446	1,140,201
Income tax expense	(143,330)	(111,974)	(15,839)
Earnings available to common stockholders	$ 628,707	$ 924,472	$ 1,124,362
U-Haul Holding Company [Member] | Nonvoting Common Stock [Member]
Expenses:
Basic earnings per common share	$ 3.22	$ 4.62	$ 5.58
Diluted earnings per common share	$ 3.22	$ 4.62	$ 5.58
Weighted average common shares outstanding: basic	176,470,092	176,470,092	176,470,092
Weighted average common shares outstanding: diluted	176,470,092	176,470,092	176,470,092
U-Haul Holding Company [Member] | Common stocks [Member]
Expenses:
Basic earnings per common share	$ 3.04	$ 5.54	$ 7.08
Diluted earnings per common share	$ 3.04	$ 5.54	$ 7.08
Weighted average common shares outstanding: basic	19,607,788	19,607,788	19,607,788
Weighted average common shares outstanding: diluted	19,607,788	19,607,788	19,607,788