Long-term Debt Borrowings, Text Portion (Details) (USD $)			6 Months Ended
	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2013 Mortgages U-Haul Guarantor Amerco Real Estate, Subsidiaries, and U-Haul Co. of Florida	Sep. 30, 2013 Line of Credit U-Haul Int'l and Amerco Guarantor Amerco Real Estate and U-Haul Company of Florida	Sep. 30, 2013 Construction Loans U-Haul Int'l and Amerco Guarantor Amerco Real Estate and Subsidiaries of U-Haul Int'l	Sep. 30, 2013 Senior Mortgage Amerco Real Estate and U-Haul Int'l Guarantor Various Subsidiaries of Amerco Real Estate and U-Haul Int'l	Sep. 30, 2013 Capital Lease Obligations U-Haul Int'l and Amerco Guarantor Amerco Real Estate Company	Sep. 30, 2013 Rental Truck (Amortizing Credit) First Loan U-Haul Int'l and Amerco Guarantor U-Haul Int'l and Subsidiaries	Sep. 30, 2013 Rental Truck (Amortizing Credit) Second Loan U-Haul Int'l and Amerco Guarantor U-Haul Int'l and Subsidiaries	Sep. 30, 2013 Cargo Van and Pickup Acquisitions Amerco Real Estate and U-Haul Int'l Guarantor Subsidiaries of U-Haul Int'l	Sep. 30, 2013 Securitization First Loan U-Haul S Fleet, 2007 Box Truck Note	Sep. 30, 2013 Securitization Second Loan U-Haul S Fleet, 2010 Box Truck Note	Sep. 30, 2013 Capital Leases for New Equipment AMERCO	Sep. 30, 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%								5.56%	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			0.19%		0.18%			0.18%
LIBOR - highest rate								0.19%
Applicable margin interest rate			1.50%	1.25%	1.90%		1.25%
Debt instrument, interest rate at period end			1.69%		2.08%
Applicable margin, per loan agreement, minimum rate								0.90%
Applicable margin, per loan agreement, maximum rate								2.63%
Applicable margins, low rate								0.90%
Applicable margins, high 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	1,775,119,000	1,661,845,000	255,000,000		24,200,000	547,000,000		258,300,000	77,400,000	115,000,000	73,100,000	97,500,000	371,800,000	39,800,000
Subsidiary holdings of parent company debt														$ 6,400,000
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	Feb. 25, 2014	Oct. 25, 2017
Debt instrument, maturity date range, start						Jul. 01, 2015		Feb. 10, 2014						Oct. 01, 2013
Debt instrument, maturity date range, end						Jan. 01, 2038		Jul. 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