Consolidated Statement of Operations by Industry Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2014		Dec. 31, 2013
Revenues:
Self-moving equipment rentals	$ 487,415		$ 436,207		$ 1,716,424		$ 1,556,787
Self-storage revenues	53,503		46,120		155,623		133,791
Self-moving and self-storage products and service sales	49,081		47,045		191,603		183,115
Property management fees	7,497		7,133		18,970		17,586
Life insurance premiums	39,026		39,198		115,997		119,708
Property and casualty insurance premiums	13,584		12,219		35,665		31,052
Net investment and interest income	20,752		20,887		63,654		59,836
Other revenue	35,497		36,522		133,865		131,636
Total revenues	706,355		645,331		2,431,801		2,233,511
Costs and expenses:
Operating expenses	338,692		322,106		1,085,961		1,002,621
Commission expenses	58,439		50,679		200,939		182,068
Cost of sales	30,751		28,229		112,215		98,331
Benefits and losses	40,084		38,630		120,426		119,255
Amortization of deferred policy acquisition costs	4,722		4,457		13,196		14,197
Lease expense	18,705		24,468		60,950		77,293
Depreciation, net of (gains) losses on disposals	81,810		70,789		209,927		191,431
Total costs and expenses	573,203		539,358		1,803,614		1,685,196
Earnings (loss) from operations before equity in earnings of subsidiaries	133,152		105,973		628,187		548,315
Equity in earnings of subsidiaries	0		0
Earnings from operations	133,152		105,973		628,187		548,315
Interest income (expense)	(25,719)		(23,607)		(74,744)		(70,053)
Fees And Amortization On Early Extinguishment Of Debt					(4,081)
Pretax earnings	107,433		82,366		549,362		478,262
Income tax expense	(40,893)		(30,145)		(202,101)		(175,082)
Earnings available to common shareholders	66,540		52,221		347,261		303,180
Operating Segments [Member] | Moving and Storage Consolidations [Member]
Revenues:
Self-moving equipment rentals	488,505		437,117		1,719,200		1,558,857
Self-storage revenues	53,503		46,120		155,623		133,791
Self-moving and self-storage products and service sales	49,081		47,045		191,603		183,115
Property management fees	7,497		7,133		18,970		17,586
Life insurance premiums	0		0		0		0
Property and casualty insurance premiums	0		0		0		0
Net investment and interest income	2,838		5,165		10,785		11,948
Other revenue	34,409		35,582		130,718		129,467
Total revenues	635,833		578,162		2,226,899		2,034,764
Costs and expenses:
Operating expenses	328,187		311,778		1,053,584		973,214
Commission expenses	58,439		50,679		200,939		182,068
Cost of sales	30,751		28,229		112,215		98,331
Benefits and losses	0		0		0		0
Amortization of deferred policy acquisition costs	0		0		0		0
Lease expense	18,755		24,514		61,090		77,430
Depreciation, net of (gains) losses on disposals	81,810		70,789		209,927		191,431
Total costs and expenses	517,942		485,989		1,637,755		1,522,474
Earnings (loss) from operations before equity in earnings of subsidiaries	117,891		92,173		589,144		512,290
Equity in earnings of subsidiaries	10,088		9,281		25,763		23,864
Earnings from operations	127,979		101,454		614,907		536,154
Interest income (expense)	(25,875)		(23,752)		(75,218)		(70,376)
Fees And Amortization On Early Extinguishment Of Debt					(4,081)
Pretax earnings	102,104		77,702		535,608		465,778
Income tax expense	(35,564)		(25,481)		(188,347)		(162,598)
Earnings available to common shareholders	66,540		52,221		347,261		303,180
Operating Segments [Member] | Moving and Storage Consolidations [Member] | AMERCO [Member]
Revenues:
Self-moving equipment rentals	0		0		0		0
Self-storage revenues	0		0		0		0
Self-moving and self-storage products and service sales	0		0		0		0
Property management fees	0		0		0		0
Life insurance premiums	0		0		0		0
Property and casualty insurance premiums	0		0		0		0
Net investment and interest income	1,234		2,516		3,687		5,031
Other revenue	0		260		0		260
Total revenues	1,234		2,776		3,687		5,291
Costs and expenses:
Operating expenses	1,502		1,782		5,286		6,067
Commission expenses	0		0		0		0
Cost of sales	0		0		0		0
Benefits and losses	0		0		0		0
Amortization of deferred policy acquisition costs	0		0		0		0
Lease expense	24		23		70		69
Depreciation, net of (gains) losses on disposals	1		1		4		4
Total costs and expenses	1,527		1,806		5,360		6,140
Earnings (loss) from operations before equity in earnings of subsidiaries	(293)		970		(1,673)		(849)
Equity in earnings of subsidiaries	56,559		38,578		313,319		263,524
Earnings from operations	56,266		39,548		311,646		262,675
Interest income (expense)	16,139		20,687		55,551		63,796
Fees And Amortization On Early Extinguishment Of Debt					0
Pretax earnings	72,405		60,235		367,197		326,471
Income tax expense	(5,865)		(8,014)		(19,936)		(23,291)
Earnings available to common shareholders	66,540		52,221		347,261		303,180
Operating Segments [Member] | Moving and Storage Consolidations [Member] | Uhaul [Member]
Revenues:
Self-moving equipment rentals	488,505		437,117		1,719,200		1,558,857
Self-storage revenues	53,121		45,818		154,664		132,906
Self-moving and self-storage products and service sales	49,081		47,045		191,603		183,115
Property management fees	7,497		7,133		18,970		17,586
Life insurance premiums	0		0		0		0
Property and casualty insurance premiums	0		0		0		0
Net investment and interest income	1,371		1,988		5,326		6,183
Other revenue	36,040		37,021		135,713		134,181
Total revenues	635,615		576,122		2,225,476		2,032,828
Costs and expenses:
Operating expenses	354,219		334,489		1,128,472		1,039,399
Commission expenses	58,439		50,679		200,939		182,068
Cost of sales	30,751		28,229		112,215		98,331
Benefits and losses	0		0		0		0
Amortization of deferred policy acquisition costs	0		0		0		0
Lease expense	18,695		24,482		60,958		77,317
Depreciation, net of (gains) losses on disposals	75,573		66,340		192,760		179,241
Total costs and expenses	537,677		504,219		1,695,344		1,576,356
Earnings (loss) from operations before equity in earnings of subsidiaries	97,938		71,903		530,132		456,472
Equity in earnings of subsidiaries	0		0		0		0
Earnings from operations	97,938		71,903		530,132		456,472
Interest income (expense)	(20,836)		(26,371)		(69,977)		(83,442)
Fees And Amortization On Early Extinguishment Of Debt					0
Pretax earnings	77,102		45,532		460,155		373,030
Income tax expense	(30,056)		(16,995)		(170,018)		(137,033)
Earnings available to common shareholders	47,046		28,537		290,137		235,997
Operating Segments [Member] | Moving and Storage Consolidations [Member] | Real Estate [Member]
Revenues:
Self-moving equipment rentals	0		0		0		0
Self-storage revenues	382		302		959		885
Self-moving and self-storage products and service sales	0		0		0		0
Property management fees	0		0		0		0
Life insurance premiums	0		0		0		0
Property and casualty insurance premiums	0		0		0		0
Net investment and interest income	233		661		1,772		734
Other revenue	29,405		26,091		85,795		76,085
Total revenues	30,020		27,054		88,526		77,704
Costs and expenses:
Operating expenses	3,502		3,297		10,616		8,807
Commission expenses	0		0		0		0
Cost of sales	0		0		0		0
Benefits and losses	0		0		0		0
Amortization of deferred policy acquisition costs	0		0		0		0
Lease expense	36		9		62		44
Depreciation, net of (gains) losses on disposals	6,236		4,448		17,163		12,186
Total costs and expenses	9,774		7,754		27,841		21,037
Earnings (loss) from operations before equity in earnings of subsidiaries	20,246		19,300		60,685		56,667
Equity in earnings of subsidiaries	0		0		0		0
Earnings from operations	20,246		19,300		60,685		56,667
Interest income (expense)	(21,178)		(18,068)		(60,792)		(50,730)
Fees And Amortization On Early Extinguishment Of Debt					(4,081)
Pretax earnings	(932)		1,232		(4,188)		5,937
Income tax expense	357		(472)		1,607		(2,274)
Earnings available to common shareholders	(575)		760		(2,581)		3,663
Operating Segments [Member] | Moving and Storage Consolidations [Member] | Moving and Storage Operating Eliminations [Member]
Revenues:
Self-moving equipment rentals	0		0		0		0
Self-storage revenues	0		0		0		0
Self-moving and self-storage products and service sales	0		0		0		0
Property management fees	0		0		0		0
Life insurance premiums	0		0		0		0
Property and casualty insurance premiums	0		0		0		0
Net investment and interest income	0		0		0		0
Other revenue	(31,036)	[1]	(27,790)	[1]	(90,790)	[1]	(81,059)	[1]
Total revenues	(31,036)		(27,790)		(90,790)		(81,059)
Costs and expenses:
Operating expenses	(31,036)	[1]	(27,790)	[1]	(90,790)	[1]	(81,059)	[1]
Commission expenses	0		0		0		0
Cost of sales	0		0		0		0
Benefits and losses	0		0		0		0
Amortization of deferred policy acquisition costs	0		0		0		0
Lease expense	0		0		0		0
Depreciation, net of (gains) losses on disposals	0		0		0		0
Total costs and expenses	(31,036)		(27,790)		(90,790)		(81,059)
Earnings (loss) from operations before equity in earnings of subsidiaries	0		0		0		0
Equity in earnings of subsidiaries	(46,471)	[2]	(29,297)	[2]	(287,556)	[2]	(239,660)	[2]
Earnings from operations	(46,471)		(29,297)		(287,556)		(239,660)
Interest income (expense)	0		0		0		0
Fees And Amortization On Early Extinguishment Of Debt					0
Pretax earnings	(46,471)		(29,297)		(287,556)		(239,660)
Income tax expense	0		0		0		0
Earnings available to common shareholders	(46,471)		(29,297)		(287,556)		(239,660)
Operating Segments [Member] | Property and Casualty Insurance [Member]
Revenues:
Self-moving equipment rentals	0	[3]	0	[1],[4],[5]	0	[6]	0	[7]
Self-storage revenues	0	[3]	0	[1],[4],[5]	0	[6]	0	[7]
Self-moving and self-storage products and service sales	0	[3]	0	[5]	0	[6]	0	[7]
Property management fees	0	[3]	0	[5]	0	[6]	0	[7]
Life insurance premiums	0	[3]	0	[5]	0	[6]	0	[7]
Property and casualty insurance premiums	13,584	[3]	12,219	[5]	35,665	[6]	31,052	[7]
Net investment and interest income	2,961	[3]	3,009	[5]	9,823	[6]	7,949	[7]
Other revenue	0	[3]	0	[5]	0	[6]	0	[7]
Total revenues	16,545	[3]	15,228	[5]	45,488	[6]	39,001	[7]
Costs and expenses:
Operating expenses	6,123	[3]	5,223	[5]	18,635	[6]	13,738	[7]
Commission expenses	0	[3]	0	[5]	0	[6]	0	[7]
Cost of sales	0	[3]	0	[5]	0	[6]	0	[7]
Benefits and losses	3,481	[3]	4,289	[5]	8,918	[6]	8,746	[7]
Amortization of deferred policy acquisition costs	0	[3]	0	[5]	0	[6]	0	[7]
Lease expense	0	[3]	0	[5]	0	[6]	0	[7]
Depreciation, net of (gains) losses on disposals	0	[3]	0	[5]	0	[6]	0	[7]
Total costs and expenses	9,604	[3]	9,512	[5]	27,553	[6]	22,484	[7]
Earnings (loss) from operations before equity in earnings of subsidiaries	6,941	[3]	5,716	[5]	17,935	[6]	16,517	[7]
Equity in earnings of subsidiaries	0	[3]	0	[5]	0	[6]	0	[7]
Earnings from operations	6,941	[3]	5,716	[5]	17,935	[6]	16,517	[7]
Interest income (expense)	0	[3]	0	[5]	0		0	[1],[4],[7]
Fees And Amortization On Early Extinguishment Of Debt					0	[6]
Pretax earnings	6,941	[3]	5,716	[5]	17,935	[6]	16,517	[7]
Income tax expense	(2,428)	[3]	(2,000)	[5]	(6,277)	[6]	(5,780)	[7]
Earnings available to common shareholders	4,513	[3]	3,716	[5]	11,658	[6]	10,737	[7]
Operating Segments [Member] | Life Insurance [Member]
Revenues:
Self-moving equipment rentals	0	[3]	0	[5]	0	[6]	0	[7]
Self-storage revenues	0	[3]	0	[5]	0	[6]	0	[7]
Self-moving and self-storage products and service sales	0	[3]	0	[5]	0	[6]	0	[7]
Property management fees	0	[3]	0	[5]	0	[6]	0	[7]
Life insurance premiums	39,026	[3]	39,198	[5]	115,997	[6]	119,708	[7]
Property and casualty insurance premiums	0	[3]	0	[5]	0	[6]	0	[7]
Net investment and interest income	15,149	[3]	12,895	[5]	43,632	[6]	40,372	[7]
Other revenue	1,202	[3]	1,059	[5]	3,491	[6]	2,524	[7]
Total revenues	55,377	[3]	53,152	[5]	163,120	[6]	162,604	[7]
Costs and expenses:
Operating expenses	5,576	[3]	6,125	[5]	16,834	[6]	18,067	[7]
Commission expenses	0	[3]	0	[5]	0	[6]	0	[7]
Cost of sales	0	[3]	0	[5]	0	[6]	0	[7]
Benefits and losses	36,603	[3]	34,341	[5]	111,508	[6]	110,509	[7]
Amortization of deferred policy acquisition costs	4,722	[3]	4,457	[5]	13,196	[6]	14,197	[7]
Lease expense	0	[3]	0	[5]	0	[6]	0	[7]
Depreciation, net of (gains) losses on disposals	0	[3]	0	[5]	0	[6]	0	[7]
Total costs and expenses	46,901	[3]	44,923	[5]	141,538	[6]	142,773	[7]
Earnings (loss) from operations before equity in earnings of subsidiaries	8,476	[3]	8,229	[5]	21,582	[6]	19,831	[7]
Equity in earnings of subsidiaries	0	[3]	0	[5]	0	[6]	0	[7]
Earnings from operations	8,476	[3]	8,229	[5]	21,582	[6]	19,831	[7]
Interest income (expense)	0	[3]	0	[5]	0		0	[7]
Fees And Amortization On Early Extinguishment Of Debt					0	[6]
Pretax earnings	8,476	[3]	8,229	[5]	21,582	[6]	19,831	[7]
Income tax expense	(2,901)	[3]	(2,664)	[5]	(7,477)	[6]	(6,704)	[7]
Earnings available to common shareholders	5,575	[3]	5,565	[5]	14,105	[6]	13,127	[7]
Consolidation, Eliminations [Member]
Revenues:
Self-moving equipment rentals	(1,090)	[4]	(910)	[4]	(2,776)	[4]	(2,070)	[4]
Self-storage revenues	0		0		0		0
Self-moving and self-storage products and service sales	0		0		0		0
Property management fees	0		0		0		0
Life insurance premiums	0		0		0		0
Property and casualty insurance premiums	0		0		0		0
Net investment and interest income	(196)	[1]	(182)	[1]	(586)	[1]	(433)	[1]
Other revenue	(114)	[1]	(119)	[1]	(344)	[1]	(355)	[1]
Total revenues	(1,400)		(1,211)		(3,706)		(2,858)
Costs and expenses:
Operating expenses	(1,194)	[7]	(1,020)	[1],[4],[7]	(3,092)	[1],[4],[5]	(2,398)	[1],[4],[5]
Commission expenses	0		0		0		0
Cost of sales	0		0		0		0
Benefits and losses	0		0		0		0
Amortization of deferred policy acquisition costs	0		0		0		0
Lease expense	(50)	[1]	(46)	[1]	(140)	[1]	(137)	[1]
Depreciation, net of (gains) losses on disposals	0		0		0		0
Total costs and expenses	(1,244)		(1,066)		(3,232)		(2,535)
Earnings (loss) from operations before equity in earnings of subsidiaries	(156)		(145)		(474)		(323)
Equity in earnings of subsidiaries	(10,088)	[2]	(9,281)	[2]	(25,763)	[2]	(23,864)	[2]
Earnings from operations	(10,244)		(9,426)		(26,237)		(24,187)
Interest income (expense)	156	[1]	145	[1]	474	[1]	323	[1]
Fees And Amortization On Early Extinguishment Of Debt					0
Pretax earnings	(10,088)		(9,281)		(25,763)		(23,864)
Income tax expense	0		0		0		0
Earnings available to common shareholders	$ (10,088)		$ (9,281)		$ (25,763)		$ (23,864)

[1] Eliminate intercompany lease / interest income

[2] Eliminate equity in earnings of subsidiaries

[3] Balances for the quarter ended September 30, 2014

[4] Eliminate intercompany premiums

[5] Balances for the quarter ended September 30, 2013

[6] Balances for the nine months ended September 30, 2014

[7] Balances for the nine months ended September 30, 2013