Long-term Debt Borrowings, Text Portion (Details) (USD $)			9 Months Ended					9 Months Ended
	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2013 Mortgages Amerco Real Estate, Subsidiaries, and U-Haul Co. of Florida	Dec. 31, 2013 Line of Credit U-Haul Int'l and Amerco Guarantor Amerco Real Estate and U-Haul Company of Florida	Dec. 31, 2013 Construction Loans U-Haul Int'l and Amerco Guarantor Amerco Real Estate and Subsidiaries of U-Haul Int'l	Dec. 31, 2013 Senior Mortgage - Loan 1 Amerco Real Estate and U-Haul Int'l Guarantor Various Subsidiaries of Amerco Real Estate and U-Haul Int'l	Dec. 31, 2013 Senior Mortgage - Subset of Loan 1 Amerco Real Estate and U-Haul Int'l Guarantor Various Subsidiaries of Amerco Real Estate and U-Haul Int'l	Dec. 31, 2013 Capital Lease Obligations U-Haul Int'l and Amerco Guarantor Amerco Real Estate Company	Dec. 31, 2013 Rental Truck (Amortizing Credit) First Loan U-Haul Int'l and Amerco Guarantor U-Haul Int'l and Subsidiaries	Dec. 31, 2013 Rental Truck (Amortizing Credit) Second Loan U-Haul Int'l and Amerco Guarantor U-Haul Int'l and Subsidiaries	Dec. 31, 2013 New Truck Acquisitions U-Haul Int'l and Amerco Guarantor Subsidiaries of U-Haul Int'l	Dec. 31, 2013 Securitization First Loan U-Haul S Fleet, 2007 Box Truck Note	Dec. 31, 2013 Securitization Second Loan U-Haul S Fleet, 2010 Box Truck Note	Dec. 31, 2013 Capital Leases for New Equipment AMERCO	Dec. 31, 2013 U-Haul Investor Club Amerco and US Bank, National Association, the Trustee
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%			6.14%	3.94%	3.53%				8.00%
Debt instruments, interest rate, effective percentage:
LIBOR			0.17%		0.17%		0.17%		0.16%
LIBOR - highest rate									0.17%
Applicable margin interest rate			1.50%	1.25%	1.90%		2.50%	1.25%
Debt instrument, interest rate at period end			1.67%		2.07%		2.67%
Applicable margin, per loan agreement, minimum rate									0.90%
Applicable margin, per loan agreement, maximum rate									2.63%
Debt instruments, face, payment, and remaining balance amount:
Debt instrument, face amount											$ 115,000,000
Debt instrument, original face amount											85,000,000
Debt instrument, increase in face amount											95,000,000
Debt instrument, associate another note amount											20,000,000
Line of credit facility, maximum borrowing capacity				100,000,000	26,100,000			25,000,000				217,000,000	155,000,000
Line of credit, current borrowing capacity				50,000,000
Line of credit facility, remaining borrowing capacity				50,000,000				25,000,000
Notes, loans and leases payable subtotal, calculated using applicable margin plus LIBOR			25,800,000
Notes, loans and leases payable subtotal, calculated using fixed rate swap rate			226,700,000
Notes, loans and leases payable	1,862,869,000	1,661,845,000	252,500,000		7,000,000	691,600,000	99,300,000		275,100,000	103,000,000	115,000,000	0	93,800,000	390,400,000	43,600,000
Subsidiary holdings of parent company debt															$ 6,100,000
Debt instruments, issuance and maturity dates:
Mortgage loans on real estate, final maturity date			Apr. 10, 2023	Apr. 30, 2014	Jun. 30, 2016
Debt instrument, maturity date								Apr. 30, 2015			Aug. 26, 2016		Oct. 25, 2017
Debt instrument, maturity date range, start						Jul. 01, 2015			Feb. 10, 2014						Oct. 01, 2014
Debt instrument, maturity date range, end						Jan. 01, 2038			Sep. 01, 2020						May 31, 2043
Debt instrument, issuance date				Apr. 29, 2011	Jun. 29, 2006						Dec. 31, 2009	Jun. 01, 2007	Oct. 28, 2010		Feb. 28, 2011
Loan modification and extension date					Jun. 27, 2011						May 31, 2017
Term note amended date				Feb. 28, 2013				Feb. 28, 2013			Aug. 26, 2011
Debt instrument, earliest issuance date														Apr. 29, 2008
Debt instrument, latest issuance date											Dec. 22, 2011
Purchase equipment through fiscal year												2008
Debt instruments, miscellaneous information:
Terms of lease														Between 3 and 7 years
Optional extension				1 year 0 months 0 days