Schedule I - Condensed Financial Information of U-Haul Holding Company (Balance Sheets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
ASSETS:
Cash and cash equivalents	$ 1,534,544	$ 2,060,524
Related party assets	57,934	48,308
Total assets	19,058,758	18,100,734	$ 17,327,183	$ 14,651,606	$ 14,693,044
Liabilities
Total liabilities	11,886,313	11,596,543		9,732,515	9,846,608
Stockholders' equity:
Additional paid-in capital	462,548	453,643
Accumulated other comprehensive income (loss)	223,216	285,623		106,857	42,319
Consolidated statement of change in equity
Beginning of period	7,003,148		5,025,568
Net Income (Loss)	628,707	924,472	1,124,362
Series N Non-Voting Common Stock Dividends	(31,765)	(14,117)	0
End of period	7,600,090	7,003,148
Total stockholders' equity	7,172,445	6,504,191		4,919,091	4,846,436
Total liabilities and stockholders' equity	19,058,758	18,100,734		$ 14,651,606	$ 14,693,044
Nonvoting Common Stock [Member]
Stockholders' equity:
Common stock	176	176
Consolidated statement of change in equity
Net Income (Loss)	0	0	0
Series N Non-Voting Common Stock Dividends	0	0
Common Stock in Treasury [Member]
Consolidated statement of change in equity
Cost of shares in treasury	(525,653)	(525,653)
Preferred Stock in Treasury [Member]
Consolidated statement of change in equity
Cost of shares in treasury	(151,997)	(151,997)
U-Haul Holding Company [Member]
ASSETS:
Cash and cash equivalents	975,109	1,662,790
Investments in subsidiaries	4,784,174	4,551,742
Related party assets	3,856,766	2,482,280
Other assets	253,133	403,191
Total assets	9,869,182	9,100,003
Liabilities
Other liabilities	2,702,780	2,601,631
Total liabilities	2,702,780	2,601,631
Stockholders' equity:
Preferred stock	0	0
Common stock	10,497	10,497
Additional paid-in capital	462,758	453,853
Accumulated other comprehensive income (loss)	229,259	291,442
Consolidated statement of change in equity
Beginning of period	7,002,938	6,112,191
Net Income (Loss)	628,707	924,472	1,124,362
Dividends		(19,608)
Series N Non-Voting Common Stock Dividends	(31,765)	(14,117)
End of period	7,599,880	7,002,938	$ 6,112,191
Total stockholders' equity	7,166,402	6,498,372
Total liabilities and stockholders' equity	9,869,182	9,100,003
U-Haul Holding Company [Member] | Nonvoting Common Stock [Member]
Stockholders' equity:
Common stock	176	176
U-Haul Holding Company [Member] | Common Stock in Treasury [Member]
Consolidated statement of change in equity
Cost of shares in treasury	(525,653)	(525,653)
U-Haul Holding Company [Member] | Preferred Stock in Treasury [Member]
Consolidated statement of change in equity
Cost of shares in treasury	$ (151,997)	$ (151,997)