Consolidated Cash Flow Statement by Industry Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2012		Jun. 30, 2011
Cash flow from operating activities:
Net earnings	$ 80,569		$ 78,223
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	63,641		54,068
Amortization of deferred policy acquisition costs	2,811		4,375
Change in allowance for losses on trade receivables	(102)		135
Change in allowance for inventory reserves	695		1,377
Net gain on sale of real and personal property	(7,516)		(9,710)
Net gain on sale of investments	39		(3,516)
Deferred income taxes	4,641		32,446
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	23,486		(37,146)
Inventories	(5,398)		(393)
Prepaid expenses	267		1,150
Capitalization of deferred policy acquisition costs	(5,420)		(4,518)
Other assets	20,518		10,586
Related party assets	139,519		(3,198)
Accounts payable and accrued expenses	47,981		17,534
Policy benefits and losses, claims and loss expenses payable	(24,242)		4,517
Other policyholders' funds and liabilities	(1,884)		(1,084)
Deferred income	6,457		8,328
Related party liabilities	1,531		245
Net cash provided by operating activities	347,593		153,419
Purchase of:
Property, plant and equipment	(157,786)		(215,779)
Short term investments	(55,075)		(66,363)
Equity securities			(8,759)
Real estate			(12)
Mortgage loans	(14,452)		(36,202)
Proceeds from sale of:
Property, plant and equipment	62,426		55,010
Short term investments	66,393		79,877
Equity securities			8,800
Real estate	4		34
Mortgage loans	11,547		17,992
Net cash used by investing activities	(112,515)		(173,967)
Cash flow from financing activities:
Borrowings from credit facilities	26,187		58,558
Principal repayments on credit facilities	(61,142)		(42,252)
Debt issuance costs			(560)
Capital lease payments	(3,888)		(1,727)
Leveraged Employee Stock Ownership Plan - repayments from loan	162		280
Securitization deposits	(908)		27,953
Preferred stock redemption paid			(144,289)
Preferred stock dividends paid			(3,077)
Contribution to related party			(518)
Investment contract deposits	28,993		2,588
Investment contract withdrawals	(7,967)		(8,195)
Net cash used by financing activities	(18,563)		(111,239)
Effects of exchange rate on cash	(376)		44
Increase (decrease) in cash and cash equivalents	216,139		(131,743)
Cash and cash equivalents at the beginning of period	350,100		375,496
Cash and cash equivalents at the end of the period	566,239		243,753
Property and Casualty Insurance
Cash flow from operating activities:
Net earnings	1,681	[1]	1,234	[2]
Adjustments to reconcile net earnings to cash provided by operations:
Net gain on sale of investments	12	[1]	21	[2]
Deferred income taxes	(236)	[1]	210	[2]
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	38,152	[1]	(1,229)	[2]
Other assets	1,164	[1]	215	[2]
Related party assets	(222)	[1]	(7)	[2]
Policy benefits and losses, claims and loss expenses payable	(42,772)	[1]	1,726	[2]
Other policyholders' funds and liabilities	(703)	[1]	141	[2]
Related party liabilities	105	[1]	(363)	[2]
Net cash provided by operating activities	(2,819)	[1]	1,948	[2]
Purchase of:
Short term investments	(22,430)	[1]	(15,853)	[2]
Real estate			(12)	[2]
Mortgage loans	(1,821)	[1]	(11,639)	[2]
Proceeds from sale of:
Short term investments	19,710	[1]	19,134	[2]
Real estate			34	[2]
Mortgage loans	577	[1]	9,915	[2]
Net cash used by investing activities	446	[1]	2,856	[2]
Cash flow from financing activities:
Increase (decrease) in cash and cash equivalents	(2,373)	[1]	4,804	[2]
Cash and cash equivalents at the beginning of period	15,462	[3]	14,700	[2]
Cash and cash equivalents at the end of the period	13,089	[4]	19,504	[2]
Life Insurance
Cash flow from operating activities:
Net earnings	901	[1]	1,367	[2]
Adjustments to reconcile net earnings to cash provided by operations:
Amortization of deferred policy acquisition costs	2,811	[1]	4,375	[2]
Change in allowance for losses on trade receivables			2	[2]
Net gain on sale of investments	27	[1]	(3,049)	[2]
Deferred income taxes	478	[1]	2,094	[2]
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	(2,250)	[1]	(26,335)	[2]
Capitalization of deferred policy acquisition costs	(5,420)	[1]	(4,518)	[2]
Other assets	(39)	[1]	(25)	[2]
Accounts payable and accrued expenses	(645)	[1]	18,018	[2]
Policy benefits and losses, claims and loss expenses payable	11,753	[1]	12,724	[2]
Other policyholders' funds and liabilities	(1,181)	[1]	(1,225)	[2]
Related party liabilities	(21)	[1]	(28)	[2]
Net cash provided by operating activities	6,414	[1]	3,400	[2]
Purchase of:
Short term investments	(37,965)	[1]	(50,510)	[2]
Mortgage loans			(2,984)	[2]
Proceeds from sale of:
Short term investments	46,683	[1]	60,743	[2]
Real estate	4	[1]
Mortgage loans	1,868	[1]	628	[2]
Net cash used by investing activities	(19,392)	[1]	(1,965)	[2]
Cash flow from financing activities:
Investment contract deposits	28,993	[1]	2,588	[2]
Investment contract withdrawals	(7,967)	[1]	(8,195)	[2]
Net cash used by financing activities	21,026	[1]	(5,607)	[2]
Increase (decrease) in cash and cash equivalents	8,048	[1]	(4,172)	[2]
Cash and cash equivalents at the beginning of period	25,410	[3]	37,301	[2]
Cash and cash equivalents at the end of the period	33,458	[4]	33,129	[2]
Eliminations
Cash flow from operating activities:
Net earnings	(2,582)		(2,758)
Earnings from consolidated entities	2,582		2,601
Net change in other operating assets and liabilities:
Related party assets	(5,320)	[5]	(7,715)	[5]
Net cash provided by operating activities	(5,320)		(7,872)
Purchase of:
Short term investments	5,320	[5]
Mortgage loans			26,177	[5]
Proceeds from sale of:
Mortgage loans			(26,177)	[5]
Net cash used by investing activities	5,320
Cash flow from financing activities:
Preferred stock redemption paid			7,708	[5]
Preferred stock dividends paid			164	[6]
Net cash used by financing activities			7,872
Moving and Storage Consolidations
Cash flow from operating activities:
Net earnings	80,569		78,380
Earnings from consolidated entities	(2,582)		(2,601)
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	63,641		54,068
Change in allowance for losses on trade receivables	(102)		133
Change in allowance for inventory reserves	695		1,377
Net gain on sale of real and personal property	(7,516)		(9,710)
Net gain on sale of investments			(488)
Deferred income taxes	4,399		30,142
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	(12,416)		(9,582)
Inventories	(5,398)		(393)
Prepaid expenses	267		1,150
Other assets	19,393		10,396
Related party assets	145,061		4,524
Accounts payable and accrued expenses	48,626		(484)
Policy benefits and losses, claims and loss expenses payable	6,777		(9,933)
Deferred income	6,457		8,328
Related party liabilities	1,447		636
Net cash provided by operating activities	349,318		155,943
Purchase of:
Property, plant and equipment	(157,786)		(215,779)
Equity securities			(8,759)
Mortgage loans	(12,631)		(47,756)
Proceeds from sale of:
Property, plant and equipment	62,426		55,010
Equity securities			8,800
Mortgage loans	9,102		33,626
Net cash used by investing activities	(98,889)		(174,858)
Cash flow from financing activities:
Borrowings from credit facilities	26,187		58,558
Principal repayments on credit facilities	(61,142)		(42,252)
Debt issuance costs			(560)
Capital lease payments	(3,888)		(1,727)
Leveraged Employee Stock Ownership Plan - repayments from loan	162		280
Securitization deposits	(908)		27,953
Preferred stock redemption paid			(151,997)
Preferred stock dividends paid			(3,241)
Contribution to related party			(518)
Net cash used by financing activities	(39,589)		(113,504)
Effects of exchange rate on cash	(376)		44
Increase (decrease) in cash and cash equivalents	210,464		(132,375)
Cash and cash equivalents at the beginning of period	309,228		323,495
Cash and cash equivalents at the end of the period	519,692		191,120
AMERCO /NV/
Cash flow from operating activities:
Net earnings	80,569		78,380
Earnings from consolidated entities	(66,615)		(63,851)
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	1		1
Net gain on sale of investments			(488)
Deferred income taxes	4,399		30,142
Net change in other operating assets and liabilities:
Prepaid expenses	9,496		8,958
Other assets	3		160
Related party assets	(1,488)		12
Accounts payable and accrued expenses	27,709		911
Net cash provided by operating activities	54,074		54,225
Purchase of:
Equity securities			(8,759)
Proceeds from sale of:
Equity securities			8,800
Net cash used by investing activities			41
Cash flow from financing activities:
Proceeds from (repayment of) intercompany loans	(55,326)		(78,996)
Preferred stock redemption paid			(151,997)
Preferred stock dividends paid			(3,241)
Contribution to related party			(518)
Net cash used by financing activities	(55,326)		(234,752)
Increase (decrease) in cash and cash equivalents	(1,252)		(180,486)
Cash and cash equivalents at the beginning of period	201,502		250,104
Cash and cash equivalents at the end of the period	200,250		69,618
U-Haul
Cash flow from operating activities:
Net earnings	63,331		60,184
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	59,836		50,815
Change in allowance for losses on trade receivables	(102)		133
Change in allowance for inventory reserves	695		1,377
Net gain on sale of real and personal property	(7,516)		(9,414)
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	(12,416)		(9,582)
Inventories	(5,398)		(393)
Prepaid expenses	(9,063)		(7,623)
Other assets	19,649		9,108
Related party assets	146,547		4,527
Accounts payable and accrued expenses	20,736		(1,286)
Policy benefits and losses, claims and loss expenses payable	6,777		(9,933)
Deferred income	6,457		8,328
Related party liabilities	1,447		636
Net cash provided by operating activities	290,980		96,877
Purchase of:
Property, plant and equipment	(131,874)		(214,039)
Mortgage loans	(5,048)		(5)
Proceeds from sale of:
Property, plant and equipment	62,426		54,501
Mortgage loans	8,029
Net cash used by investing activities	(66,467)		(159,543)
Cash flow from financing activities:
Borrowings from credit facilities	26,187		28,558
Principal repayments on credit facilities	(55,254)		(21,673)
Debt issuance costs			(474)
Capital lease payments	(3,888)		(1,727)
Leveraged Employee Stock Ownership Plan - repayments from loan	162		280
Securitization deposits	(908)		27,953
Proceeds from (repayment of) intercompany loans	21,300		77,734
Net cash used by financing activities	(12,401)		110,651
Effects of exchange rate on cash	(376)		44
Increase (decrease) in cash and cash equivalents	211,736		48,029
Cash and cash equivalents at the beginning of period	106,951		72,634
Cash and cash equivalents at the end of the period	318,687		120,663
Real Estate
Cash flow from operating activities:
Net earnings	702		1,066
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	3,804		3,252
Net gain on sale of real and personal property			(296)
Net change in other operating assets and liabilities:
Prepaid expenses	(166)		(185)
Other assets	(259)		1,128
Related party assets	2		(15)
Accounts payable and accrued expenses	181		(109)
Net cash provided by operating activities	4,264		4,841
Purchase of:
Property, plant and equipment	(25,912)		(1,740)
Mortgage loans	(7,583)		(47,751)
Proceeds from sale of:
Property, plant and equipment			509
Mortgage loans	1,073		33,626
Net cash used by investing activities	(32,422)		(15,356)
Cash flow from financing activities:
Borrowings from credit facilities			30,000
Principal repayments on credit facilities	(5,888)		(20,579)
Debt issuance costs			(86)
Proceeds from (repayment of) intercompany loans	34,026		1,262
Net cash used by financing activities	28,138		10,597
Increase (decrease) in cash and cash equivalents	(20)		82
Cash and cash equivalents at the beginning of period	775		757
Cash and cash equivalents at the end of the period	755		839
Eliminations
Cash flow from operating activities:
Net earnings	(64,033)		(61,250)
Earnings from consolidated entities	64,033		61,250
Fixed maturities investments
Purchase of:
Payments to acquire investments	(50,553)		(75,059)
Proceeds from sale of:
Proceeds from sale of acquired investments	23,978		66,035
Fixed maturities investments | Property and Casualty Insurance
Purchase of:
Payments to acquire investments	(9,576)	[1]	(7,831)	[2]
Proceeds from sale of:
Proceeds from sale of acquired investments	12,983	[1]	8,649	[2]
Fixed maturities investments | Life Insurance
Purchase of:
Payments to acquire investments	(40,977)	[1]	(67,228)	[2]
Proceeds from sale of:
Proceeds from sale of acquired investments	10,995	[1]	57,386	[2]
Preferred stock investments
Purchase of:
Payments to acquire investments			(541)
Proceeds from sale of:
Proceeds from sale of acquired investments	1,003		1,000
Preferred stock investments | Property and Casualty Insurance
Purchase of:
Payments to acquire investments			(541)	[2]
Proceeds from sale of:
Proceeds from sale of acquired investments	$ 1,003	[1]	$ 1,000	[2]

[1] Balance for the period ended March 31, 2012

[2] Balance for the period ended March 31, 2011

[3] Balances as of December 31, 2011

[4] Balances as of March 31, 2012

[5] Eliminate intercompany investments

[6] Eliminate preferred stock dividends paid to affiliate