Schedule I - Condensed Financial Information of AMERCO (Statements of Operations) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Revenues:
Net interest income from subs	$ 5,739,747	$ 4,541,985	$ 3,978,868
Expenses:
Operating expenses	2,676,541	2,187,684	2,117,148
Total costs and expenses	4,094,750	3,580,838	3,438,740
Equity in earnings of subsidiaries	0	0	0
Pretax earnings	1,475,497	796,658	378,124
Income tax expense	(352,211)	(185,802)	63,924
Earnings available to common shareholders	$ 1,123,286	$ 610,856	$ 442,048
Basic and diluted earnings per common share	$ 57.29	$ 31.15	$ 22.55
Weighted average common shares outstanding: basic and diluted	19,607,788	19,607,788	19,603,708
Amerco [Member]
Revenues:
Net interest income from subs	$ 1,516	$ 720	$ 6,586
Expenses:
Operating expenses	5,517	6,753	10,622
Other expenses	115	115	96
Total costs and expenses	5,632	6,868	10,718
Equity in earnings of subsidiaries	1,011,841	508,632	205,940
Interest income	131,400	135,673	130,670
Pretax earnings	1,139,125	638,157	332,478
Income tax expense	(15,839)	(27,301)	109,570
Earnings available to common shareholders	$ 1,123,286	$ 610,856	$ 442,048
Basic and diluted earnings per common share	$ 57.29	$ 31.15	$ 22.55
Weighted average common shares outstanding: basic and diluted	19,607,788	19,607,788	19,603,708