Consolidated Statement of Operations by Industry Segment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Mar. 31, 2011
Revenues:
Self-moving equipment rentals	$ 1,767,520		$ 1,678,256		$ 1,547,015
Self-storage revenues	152,660		134,376		120,698
Self-moving and self-storage products and service sales	221,117		213,854		205,570
Property management fees	24,378		23,266		22,132
Life insurance premiums	178,115		277,562		206,992
Property and casualty insurance premiums	34,342		32,631		30,704
Net investment and interest income	82,903		73,552		62,745
Other revenue	97,552		78,530		55,503
Total revenues	2,558,587		2,512,027		2,251,359
Costs and expenses:
Operating expenses	1,170,568		1,093,190		1,026,577
Commission expenses	228,124		212,190		190,981
Cost of sales	107,216		116,542		106,024
Benefits and losses	180,676		320,191		200,513
Amortization of deferred policy acquisition costs	17,376		13,791		9,494
Lease expense	117,448		131,215		150,809
Depreciation, net of (gains) losses on disposals	237,996		208,901		189,266
Total costs and expenses	2,059,404		2,096,020		1,873,664
Earnings from operations	499,183		416,007		377,695
Interest income (expense)	(90,696)		(90,371)		(88,381)
Total pretax earnings (loss)	408,487		325,636		289,314
Income tax expense	(143,779)		(120,269)		(105,739)
Net earnings	264,708		205,367		183,575
Less: Excess of redemption value over carrying value of preferred shares redeemed			(5,908)		(178)
Preferred stock dividends paid			(2,913)		(12,412)
Earnings available to common shareholders	264,708		196,546		170,985
Property and Casualty Insurance
Revenues:
Self-moving equipment rentals	0	[1]	0	[2]	0	[3]
Self-storage revenues	0	[1]	0	[2]	0	[3]
Self-moving and self-storage products and service sales	0	[1]	0	[2]	0	[3]
Property management fees	0	[1]	0	[2]	0	[3]
Life insurance premiums	0	[1]	0	[2]	0	[3]
Property and casualty insurance premiums	34,342	[1]	32,631	[2]	30,704	[3]
Net investment and interest income	13,858	[1]	9,955	[2]	7,959	[3]
Other revenue	0	[1]	0	[2]	0	[3]
Total revenues	48,200	[1]	42,586	[2]	38,663	[3]
Costs and expenses:
Operating expenses	18,007	[1]	13,270	[2]	15,824	[3]
Commission expenses	0	[1]	0	[2]	0	[3]
Cost of sales	0	[1]	0	[2]	0	[3]
Benefits and losses	15,999	[1]	65,742	[2]	17,201	[3]
Amortization of deferred policy acquisition costs	0	[1],[4]	0	[2]	0	[3],[5]
Lease expense	0	[1]	0	[2]	0	[3]
Depreciation, net of (gains) losses on disposals	0	[1]	0	[2]	0	[3]
Total costs and expenses	34,006	[1]	79,012	[2]	33,025	[3]
Earnings (loss) from operations before subsidiaries	14,194	[1]	(36,426)	[2]	5,638	[3]
Equity in earnings of subsidiaries	0	[1]	0	[2]	0	[3]
Earnings from operations	14,194	[1]	(36,426)	[2]	5,638	[3]
Interest income (expense)	0	[1]	0	[2]	0	[3]
Total pretax earnings (loss)	14,194	[1]	(36,426)	[2]	5,638	[3]
Income tax expense	(4,938)	[1]	12,863	[2]	(1,831)	[3]
Net earnings	9,256	[4]	(23,563)	[2]	3,807	[3]
Less: Excess of redemption value over carrying value of preferred shares redeemed			0	[2]	0	[3]
Preferred stock dividends paid			0	[2]	0	[3]
Earnings available to common shareholders	9,256	[1]	(23,563)	[2]	3,807	[3]
Life Insurance
Revenues:
Self-moving equipment rentals	0	[1]	0	[2]	0	[3]
Self-storage revenues	0	[1]	0	[2]	0	[3]
Self-moving and self-storage products and service sales	0	[1]	0	[2]	0	[3]
Property management fees	0	[1]	0	[2]	0	[3]
Life insurance premiums	178,115	[1]	277,562	[2]	206,992	[3]
Property and casualty insurance premiums	0	[1]	0	[2]	0	[3]
Net investment and interest income	50,850	[1]	38,127	[2]	30,822	[3]
Other revenue	2,525	[1]	1,585	[2]	2,181	[3]
Total revenues	231,490	[1]	317,274	[2]	239,995	[3]
Costs and expenses:
Operating expenses	26,482	[1]	28,885	[2]	29,754	[3]
Commission expenses	0	[1]	0	[2]	0	[3]
Cost of sales	0	[1]	0	[2]	0	[3]
Benefits and losses	164,677	[1]	254,449	[2]	183,312	[3]
Amortization of deferred policy acquisition costs	17,376	[1],[4]	13,791	[2]	9,494	[3],[5]
Lease expense	0	[1]	0	[2]	0	[3]
Depreciation, net of (gains) losses on disposals	0	[1]	0	[2]	0	[3]
Total costs and expenses	208,535	[1]	297,125	[2]	222,560	[3]
Earnings (loss) from operations before subsidiaries	22,955	[1]	20,149	[2]	17,435	[3]
Equity in earnings of subsidiaries	0	[1]	0	[2]	0	[3]
Earnings from operations	22,955	[1]	20,149	[2]	17,435	[3]
Interest income (expense)	0	[1]	0	[2]	0	[3]
Total pretax earnings (loss)	22,955	[1]	20,149	[2]	17,435	[3]
Income tax expense	(7,970)	[1]	(6,964)	[2]	(6,315)	[3]
Net earnings	14,985	[4]	13,185	[2]	11,120	[3]
Less: Excess of redemption value over carrying value of preferred shares redeemed			0	[2]	0	[3]
Preferred stock dividends paid			0	[2]	0	[3]
Earnings available to common shareholders	14,985	[1]	13,185	[2]	11,120	[3]
Eliminations
Revenues:
Self-moving equipment rentals	(1,538)	[6]	(1,707)	[6]	(2,043)	[6]
Self-storage revenues	0		0		0
Self-moving and self-storage products and service sales	0		0		0
Property management fees	0		0		0
Life insurance premiums	0		0		0
Property and casualty insurance premiums	0		0		0
Net investment and interest income	(427)	[7]	(1,662)	[8],[9]	(1,738)	[8],[9]
Other revenue	(1,480)	[7]	(1,387)	[8]	(1,344)	[8]
Total revenues	(3,445)		(4,756)		(5,125)
Costs and expenses:
Operating expenses	(2,984)	[6],[7]	(3,087)	[6],[8]	(3,353)	[6],[8]
Commission expenses	0		0		0
Cost of sales	0		0		0
Benefits and losses	0		0		0
Amortization of deferred policy acquisition costs	0		0		0
Lease expense	(167)	[7]	(1,187)	[8]	(1,221)	[8]
Depreciation, net of (gains) losses on disposals	0		0		0
Total costs and expenses	(3,151)		(4,274)		(4,574)
Earnings (loss) from operations before subsidiaries	(294)		(482)		(551)
Equity in earnings of subsidiaries	(24,241)	[10]	10,378	[10]	(14,927)	[10]
Earnings from operations	(24,535)		9,896		(15,478)
Interest income (expense)	294	[7]	154		0
Total pretax earnings (loss)	(24,241)		10,050		(15,478)
Income tax expense	0		0		0
Net earnings	(24,241)		10,050		(15,478)
Less: Excess of redemption value over carrying value of preferred shares redeemed			0		(178)
Preferred stock dividends paid			328	[9]	551	[9]
Earnings available to common shareholders	(24,241)		10,378		(15,105)
Moving and Storage Operating Segment
Revenues:
Self-moving equipment rentals	1,769,058		1,679,963		1,549,058
Self-storage revenues	152,660		134,376		120,698
Self-moving and self-storage products and service sales	221,117		213,854		205,570
Property management fees	24,378		23,266		22,132
Life insurance premiums	0		0		0
Property and casualty insurance premiums	0		0		0
Net investment and interest income	18,622		27,132		25,702
Other revenue	96,507		78,332		54,666
Total revenues	2,282,342		2,156,923		1,977,826
Costs and expenses:
Operating expenses	1,129,063		1,054,122		984,352
Commission expenses	228,124		212,190		190,981
Cost of sales	107,216		116,542		106,024
Benefits and losses	0		0		0
Amortization of deferred policy acquisition costs	0		0		0
Lease expense	117,615		132,402		152,030
Depreciation, net of (gains) losses on disposals	237,996		208,901		189,266
Total costs and expenses	1,820,014		1,724,157		1,622,653
Earnings (loss) from operations before subsidiaries	462,328		432,766		355,173
Equity in earnings of subsidiaries	24,241		(10,378)		14,927
Earnings from operations	486,569		422,388		370,100
Interest income (expense)	(90,990)		(90,525)		(88,381)
Total pretax earnings (loss)	395,579		331,863		281,719
Income tax expense	(130,871)		(126,168)		(97,593)
Net earnings	264,708		205,695		184,126
Less: Excess of redemption value over carrying value of preferred shares redeemed			(5,908)		0
Preferred stock dividends paid			(3,241)		(12,963)
Earnings available to common shareholders	264,708		196,546		171,163
AMERCO
Revenues:
Self-moving equipment rentals	0		0		0
Self-storage revenues	0		0		0
Self-moving and self-storage products and service sales	0		0		0
Property management fees	0		0		0
Life insurance premiums	0		0		0
Property and casualty insurance premiums	0		0		0
Net investment and interest income	5,248		5,857		5,140
Other revenue	81		228		20
Total revenues	5,329		6,085		5,160
Costs and expenses:
Operating expenses	13,611		9,081		7,489
Commission expenses	0		0		0
Cost of sales	0		0		0
Benefits and losses	0		0		0
Amortization of deferred policy acquisition costs	0		0		0
Lease expense	92		93		90
Depreciation, net of (gains) losses on disposals	5		5		9
Total costs and expenses	13,708		9,179		7,588
Earnings (loss) from operations before subsidiaries	(8,379)		(3,094)		(2,428)
Equity in earnings of subsidiaries	212,164		149,160		132,570
Earnings from operations	203,785		146,066		130,142
Interest income (expense)	91,125		94,278		85,584
Total pretax earnings (loss)	294,910		240,344		215,726
Income tax expense	(30,202)		(34,649)		(31,600)
Net earnings	264,708		205,695		184,126
Less: Excess of redemption value over carrying value of preferred shares redeemed	0		(5,908)		0
Preferred stock dividends paid			(3,241)		(12,963)
Earnings available to common shareholders	264,708		196,546		171,163
U-Haul
Revenues:
Self-moving equipment rentals	1,769,058		1,679,963		1,549,058
Self-storage revenues	151,512		133,070		119,359
Self-moving and self-storage products and service sales	221,117		213,854		205,570
Property management fees	24,378		23,266		22,132
Life insurance premiums	0		0		0
Property and casualty insurance premiums	0		0		0
Net investment and interest income	8,462		20,577		20,562
Other revenue	102,776		83,894		60,230
Total revenues	2,277,303		2,154,624		1,976,911
Costs and expenses:
Operating expenses	1,199,550		1,121,681		1,050,921
Commission expenses	228,124		212,190		190,981
Cost of sales	107,216		116,542		106,024
Benefits and losses	0		0		0
Amortization of deferred policy acquisition costs	0		0		0
Lease expense	117,491		132,286		151,918
Depreciation, net of (gains) losses on disposals	224,407		195,469		177,116
Total costs and expenses	1,876,788		1,778,168		1,676,960
Earnings (loss) from operations before subsidiaries	400,515		376,456		299,951
Equity in earnings of subsidiaries	0		0		0
Earnings from operations	400,515		376,456		299,951
Interest income (expense)	(124,012)		(132,781)		(129,516)
Total pretax earnings (loss)	276,503		243,675		170,435
Income tax expense	(96,099)		(88,096)		(60,342)
Net earnings	180,404		155,579		110,093
Less: Excess of redemption value over carrying value of preferred shares redeemed			0		0
Preferred stock dividends paid			0		0
Earnings available to common shareholders	180,404		155,579		110,093
Real Estate
Revenues:
Self-moving equipment rentals	0		0		0
Self-storage revenues	1,148		1,306		1,339
Self-moving and self-storage products and service sales	0		0		0
Property management fees	0		0		0
Life insurance premiums	0		0		0
Property and casualty insurance premiums	0		0		0
Net investment and interest income	4,912		698		0
Other revenue	88,626		80,318		77,947
Total revenues	94,686		82,322		79,286
Costs and expenses:
Operating expenses	10,878		9,468		9,473
Commission expenses	0		0		0
Cost of sales	0		0		0
Benefits and losses	0		0		0
Amortization of deferred policy acquisition costs	0		0		0
Lease expense	32		23		22
Depreciation, net of (gains) losses on disposals	13,584		13,427		12,141
Total costs and expenses	24,494		22,918		21,636
Earnings (loss) from operations before subsidiaries	70,192		59,404		57,650
Equity in earnings of subsidiaries	0		0		0
Earnings from operations	70,192		59,404		57,650
Interest income (expense)	(58,103)		(52,022)		(44,449)
Total pretax earnings (loss)	12,089		7,382		13,201
Income tax expense	(4,570)		(3,423)		(5,651)
Net earnings	7,519		3,959		7,550
Less: Excess of redemption value over carrying value of preferred shares redeemed			0		0
Preferred stock dividends paid			0		0
Earnings available to common shareholders	7,519		3,959		7,550
Eliminations
Revenues:
Self-moving equipment rentals	0		0		0
Self-storage revenues	0		0		0
Self-moving and self-storage products and service sales	0		0		0
Property management fees	0		0		0
Life insurance premiums	0		0		0
Property and casualty insurance premiums	0		0		0
Net investment and interest income	0		0		0
Other revenue	(94,976)	[7]	(86,108)	[8]	(83,531)	[8]
Total revenues	(94,976)		(86,108)		(83,531)
Costs and expenses:
Operating expenses	(94,976)	[7]	(86,108)	[8]	(83,531)	[8]
Commission expenses	0		0		0
Cost of sales	0		0		0
Benefits and losses	0		0		0
Amortization of deferred policy acquisition costs	0		0		0
Lease expense	0		0		0
Depreciation, net of (gains) losses on disposals	0		0		0
Total costs and expenses	(94,976)		(86,108)		(83,531)
Earnings (loss) from operations before subsidiaries	0		0		0
Equity in earnings of subsidiaries	(187,923)	[10]	(159,538)	[10]	(117,643)	[10]
Earnings from operations	(187,923)		(159,538)		(117,643)
Interest income (expense)	0		0		0
Total pretax earnings (loss)	(187,923)		(159,538)		(117,643)
Income tax expense	0		0		0
Net earnings	(187,923)		(159,538)		(117,643)
Less: Excess of redemption value over carrying value of preferred shares redeemed			0		0
Preferred stock dividends paid			0		0
Earnings available to common shareholders	$ (187,923)		$ (159,538)		$ (117,643)

[1] Balances for the year ended December 31, 2012

[2] Balances for the year ended December 31, 2011

[3] Balances for the year ended December 31, 2010

[4] Balance for the period ended December 31, 2012

[5] Balance for the period ended December 31, 2010

[6] Eliminate intercompany premiums

[7] Eliminate intercompany lease / interest income

[8] Eliminate intercompany lease income

[9] Elimination of preferred stock dividend paid to affiliate

[10] Eliminate equity in earnings of subsidiaries