Schedule I - Condensed Financial Information of AMERCO (Statements of Operations) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Revenues:
Net interest income from subsidiaries	$ 3,275,656	$ 3,074,531	$ 2,835,252
Expenses:
Operating expenses	1,470,047	1,479,409	1,313,674
Total costs and expenses	$ 2,408,842	$ 2,411,507	$ 2,205,038
Equity in earnings of subsidiaries
Interest Income	$ 97,903	$ 97,525	$ 92,692
Pretax earnings	768,911	561,418	537,522
Income tax expense	(279,910)	(204,677)	(195,131)
Earnings available to common shareholders	$ 489,001	$ 356,741	$ 342,391
Basic and diluted earnings per common share	$ 24.95	$ 18.21	$ 17.51
Weighted average common shares outstanding: basic and diluted	19,596,110	19,586,633	19,558,758
Amerco [Member]
Revenues:
Net interest income from subsidiaries	$ 2,420	$ 4,862	$ 6,465
Expenses:
Operating expenses	7,525	7,055	6,636
Other expenses	111	99	97
Total costs and expenses	7,636	7,154	6,733
Equity in earnings of subsidiaries	417,087	300,566	287,803
Interest Income	93,873	75,241	86,916
Pretax earnings	505,744	373,515	374,451
Income tax expense	(16,743)	(16,774)	(32,060)
Earnings available to common shareholders	$ 489,001	$ 356,741	$ 342,391
Basic and diluted earnings per common share	$ 24.95	$ 18.21	$ 17.51
Weighted average common shares outstanding: basic and diluted	19,596,110	19,586,633	19,558,758