Long-term Debt Borrowings, Textuals (Details) (USD $)			12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Mortgages [Member] Uhaul Guarantor [Member] Amerco Real Estate Subsidiaries and Uhaul Company of Florida [Member]	Mar. 31, 2014 Line of Credit [Member] Uhaul Intl, Amerco [Member] Amerco Real Estate, Uhaul Company Of Florida [Member]	Mar. 31, 2014 Construction Loans [Member] Uhaul Intl, Amerco [Member] Amerco Real Estate and Subsidiaries of Uhaul Intl [Member]	Mar. 31, 2014 Mortgage Loans on Real Estate [Member] Amerco Real Estate and U-Haul Int'l Guarantor [Member] Various Subsidiaries of Amerco Real Estate and Uhaul Intl [Member]	Mar. 31, 2014 Capital Lease Obligations [Member] Uhaul Intl, Amerco [Member] Amerco Real Estate Company [Member]	Mar. 31, 2014 Rental Truck Amortizing Credit First Loan [Member] Uhaul Intl, Amerco [Member] Uhaul Intl and Subsidiaries [Member]	Mar. 31, 2014 Rental Truck Amortizing Credit Second Loan [Member] Uhaul Intl, Amerco [Member] Uhaul Intl and Subsidiaries [Member]	Mar. 31, 2014 Cargo Van and Pickup Acquisitions [Member] Amerco Real Estate and U-Haul Int'l Guarantor [Member] Subsidiaries of Uhaul Intl [Member]	Mar. 31, 2014 Securitization First Loan [Member] Uhaul S Fleet Two Thousand and Seven Box Truck Note [Member]	Mar. 31, 2014 Securitization Second Loan [Member] Uhaul S Fleet Two Thousand Ten Box Truck Note [Member]	Mar. 31, 2014 Capital Leases for New Equipment [Member] Amerco, Business Segment [Member]	Mar. 31, 2014 Other Borrowings [Member] Amerco, Us Bank, National Association, Trustee [Member]	Mar. 31, 2014 Revolving Fleet Loan One [Member] Various Subsidiaries of Amerco Real Estate and Uhaul Intl [Member]	Mar. 31, 2014 Revolving Fleet Loan Two [Member] Various Subsidiaries of Amerco Real Estate and Uhaul Intl [Member]
Debt instruments, interest rate, stated percentage:
Debt instrument, interest rate, stated percentage			6.93%									4.90%
Debt instrument, interest rate, stated percentage rate range, minimum						4.90%		2.82%	1.95%	3.52%				3.00%
Debt instrument, interest rate, stated percentage rate range, maximum						5.75%		5.57%	3.94%	3.53%				8.00%
Debt instruments, interest rate, effective percentage:
LIBOR			0.16%			0.16%		0.15%							0.16%	0.15%
LIBOR - highest rate								0.16%
Applicable margin interest rate			1.50%	1.25%		2.50%	1.25%								1.75%	1.50%
Debt instrument, interest rate at period end			1.66%			2.66%									1.91%	1.65%
Applicable margin, per loan agreement, minimum rate								1.35%
Applicable margin, per loan agreement, maximum rate								2.50%
Debt instruments, face, payment, and remaining balance amount:
Debt instrument, face amount										$ 115,000,000
Line of credit facility, maximum borrowing capacity				50,000,000	26,100,000		25,000,000								225,000,000	125,000,000
Line of credit facility, remaining borrowing capacity			224,200,000			98,300,000	25,000,000					90,800,000	416,800,000		29,400,000	56,000,000
Current portion of loans payable			25,800,000
Capitalized assets, net book value													453,600,000
Notes, loans and leases payable	1,942,359,000	1,661,845,000	250,000,000			684,900,000		255,400,000	112,000,000	115,000,000	217,000,000	155,000,000		47,000,000	75,000,000	100,000,000
Subsidiary holdings of parent company debt														$ 7,100,000
Debt instruments, issuance and maturity dates:
Mortgage loans on real estate, final maturity date			Apr. 10, 2023	Apr. 30, 2015	Jun. 30, 2016
Debt instrument, maturity date							Apr. 30, 2016			Aug. 26, 2016		Oct. 25, 2017			Oct. 20, 2018	Oct. 20, 2017
Debt instrument, maturity date range, start						Jul. 01, 2015		May 15, 2015						Oct. 01, 2014
Debt instrument, maturity date range, end						Jan. 01, 2038		Mar. 15, 2021						May 31, 2044
Debt instrument, issuance date											Jun. 01, 2007	Oct. 28, 2010		Feb. 28, 2011
Loan modification and extension date										May 31, 2017
Debt instrument, earliest issuance date													Apr. 29, 2008
Debt instrument, latest issuance date													Mar. 15, 2004
Purchase equipment through fiscal year											2008
Debt instruments, miscellaneous information:
Terms of lease													Between 3 and 7 years