Schedule I - Condensed Financial Information of AMERCO Balance Sheets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
ASSETS:
Cash and cash equivalents	$ 495,112	$ 463,744	$ 357,180	$ 382,514
Investments in subsidiaries	0	0
Related party assets	169,624	182,035
Total assets	5,998,978	5,306,601	4,654,051
Liabilities:
Other Liabilities	4,471,610	4,077,342
Stockholders' equity:
Additional paid-in capital	444,210	438,168
Accumulated other comprehensive loss	(53,923)	(22,680)
Consolidated statement of change in equity
Beginning of period	1,482,630
Adjustment to initially apply ASU 2010-26		(1,721)
Net earnings	342,391	264,708	196,546
End of period	1,805,453	1,482,630
Total stockholders' equity	1,527,368	1,229,259
Total liabilities and stockholders' equity	5,998,978	5,306,601
Preferred Stock
Stockholders' equity:
Preferred stock
Series B Preferred Stock [Member]
Stockholders' equity:
Preferred stock
Series A Common Stock [Member]
Stockholders' equity:
Common stock
Uhaul Common Stock [Member]
Stockholders' equity:
Common stock	10,497	10,497
Cost of common shares in treasury [Member]
Consolidated statement of change in equity
Cost of shares in treasury	(525,653)	(525,653)
Cost of preferred shares in treasury [Member]
Consolidated statement of change in equity
Cost of shares in treasury	(151,997)	(151,997)
AMERCO [Member]
ASSETS:
Cash and cash equivalents	321,544	327,119	201,502	250,104
Investments in subsidiaries	493,612	240,080
Related party assets	1,150,671	1,032,124
Other assets	18,712	43,841
Total assets	1,984,539	1,643,164
Liabilities:
Other Liabilities	455,952	412,199
Stockholders' equity:
Additional paid-in capital	444,420	438,378
Accumulated other comprehensive loss	(53,923)	(22,680)
Consolidated statement of change in equity
Beginning of period	1,482,420	1,316,854
Adjustment to initially apply ASU 2010-26	0	(1,721)
Net earnings	342,391	264,708	196,546
Dividends	(19,568)	(97,421)
End of period	1,805,243	1,482,420	1,316,854
Total stockholders' equity	1,528,587	1,230,965
Total liabilities and stockholders' equity	1,984,539	1,643,164
AMERCO [Member] | Preferred Stock
Stockholders' equity:
Preferred stock	0	0
AMERCO [Member] | Uhaul Common Stock [Member]
Stockholders' equity:
Common stock	10,497	10,497
AMERCO [Member] | Cost of common shares in treasury [Member]
Consolidated statement of change in equity
Cost of shares in treasury	(525,653)	(525,653)
AMERCO [Member] | Cost of preferred shares in treasury [Member]
Consolidated statement of change in equity
Cost of shares in treasury	$ (151,997)	$ (151,997)