Schedule I - Condensed Financial Information of AMERCO (Balance Sheets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
ASSETS:
Cash and cash equivalents	$ 600,646	$ 441,850	$ 495,112	$ 463,744
Investments in subsidiaries
Related party assets	$ 85,734	$ 141,790
Total assets	8,150,725	6,872,175	5,998,978
Liabilities:
Other Liabilities	5,899,319	4,987,816
Stockholders' equity:
Additional paid-in capital	451,629	449,668
Accumulated other comprehensive loss	(60,525)	(34,365)
Consolidated statement of change in equity
Beginning of period	2,142,600
Net earnings	489,001	356,741	342,391
End of period	2,533,641	2,142,600
Total stockholders' equity	2,251,406	1,884,359
Total liabilities and stockholders' equity	8,150,725	6,872,175
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)
Amerco [Member]
ASSETS:
Cash and cash equivalents	381,690	291,550	321,544	$ 327,119
Investments in subsidiaries	1,185,021	813,735
Related party assets	1,249,835	1,225,044
Other assets	94,128	85,409
Total assets	2,910,674	2,415,738
Liabilities:
Other Liabilities	$ 653,082	$ 524,988
Stockholders' equity:
Preferred stock
Common stock	$ 10,497	$ 10,497
Additional paid-in capital	451,839	449,878
Accumulated other comprehensive loss	(60,525)	(34,365)
Consolidated statement of change in equity
Beginning of period	2,142,390	1,805,243
Net earnings	489,001	356,741	342,391
Dividends	(97,960)	(19,594)
End of period	2,533,431	2,142,390	$ 1,805,243
Total stockholders' equity	2,257,592	1,890,750
Total liabilities and stockholders' equity	2,910,674	2,415,738
Amerco [Member] | Common Stock in Treasury [Member]
Consolidated statement of change in equity
Cost of shares in treasury	(525,653)	(525,653)
Amerco [Member] | Preferred Stock in Treasury [Member]
Consolidated statement of change in equity
Cost of shares in treasury	$ (151,997)	$ (151,997)