Related Party Notes Receivable and Management Fees [Text] (Details) (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Sac Holdings [Member]
Related party notes receivable:
Notes receivable outstanding	$ 71,464,000	$ 72,397,000
Operating Segments [Member] | Moving and Storage Operating Segment | AMERCO [Member] | Sac Holdings, Mercury, Four Sac, Five Sac, Galaxy and Private Mini [Member]
Management fees revenue:
Management fees received exclusive of reimbursed expenses	25,800,000	23,700,000	22,500,000
Management fee rate, lowest	4.00%	4.00%	4.00%
Management fee rate, highest	10.00%	10.00%	10.00%
Operating Segments [Member] | Moving and Storage Operating Segment | Amerco, Uhaul Intl [Member] | Private Mini [Member]
Related party notes receivable:
Cash interest payments	5,400,000	5,400,000	5,400,000
Notes receivable outstanding	65,500,000
Largest aggregate balance in reporting period	65,900,000
Operating Segments [Member] | Moving and Storage Operating Segment | Various Subsidiaries of Amerco [Member] | Sac Holdings [Member]
Related party notes receivable:
Cash interest payments	17,200,000	12,600,000	17,800,000
Notes receivable outstanding	71,500,000
Largest aggregate balance in reporting period	$ 72,400,000
Earliest maturity year	2017	2017	2017
Latest maturity year	2019	2019	2019