Consolidated Cash Flow Statement by Industry Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2013		Jun. 30, 2012
Cash flow from operating activities:
Net earnings	$ 112,968		$ 80,569
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	68,999		63,641
Amortization of deferred policy acquisition costs	3,683		2,811
Change in allowance for losses on trade receivables	(14)		(102)
Change in allowance for inventory reserves	(935)		695
Net of (gains) losses on sale of real and personal property	(11,565)		(7,516)
Net (gain) loss on sale of investments	(1,776)		39
Deferred income tax	31,828		4,641
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	(22,715)		23,486
Inventories	(973)		(5,398)
Prepaid expenses	14,098		267
Capitalization of deferred policy acquisition costs	(7,808)		(5,420)
Other assets	(4,532)		20,518
Related party assets	24,878		144,890
Accounts payable and accrued expenses	18,162		47,981
Policy benefits and losses, claims and loss expenses payable	1,609		(24,242)
Other policyholders' funds and liabilities	(180)		(1,884)
Deferred income	7,584		6,457
Related party liabilities	5,962		1,448
Net cash provided by operating activities	239,273		352,881
Purchase of:
Property, plant and equipment	(275,156)		(157,786)
Short term investments	(64,652)		(60,395)
Fixed maturities investments	(66,855)		(50,553)
Equity securities	(388)		0
Preferred stock	(634)		0
Real estate	(131)		0
Mortgage loans	(12,904)		(14,452)
Proceeds from sale of:
Property, plant and equipment	93,239		62,426
Short term investments	64,818		59,421
Fixed maturities investments	41,491		23,978
Equity securities	904		0
Preferred stock	3,295		1,003
Real estate	0		4
Mortgage loans	23,258		11,547
Net cash used by investing activities	(193,715)		(124,807)
Cash flow from financing activities:
Borrowings from credit facilities	88,182		26,187
Principal repayments on credit facilities	(61,996)		(61,142)
Debt issuance costs	(232)		0
Capital lease payments	(10,449)		(3,888)
Leveraged Employee Stock Ownership Plan - repayments from loan	127		162
Securitization deposits	0		(908)
Investment contract deposits	34,742		28,993
Investment contract withdrawals	(6,754)		(7,967)
Net cash used by financing activities	43,620		(18,563)
Effects of exchange rate on cash	(335)		(376)
Increase (decrease) in cash and cash equivalents	88,843		209,135
Cash and cash equivalents at the beginning of period	463,744		357,180
Cash and cash equivalents at the end of the period	552,587		566,315
Operating Segments | Property and Casualty Insurance
Cash flow from operating activities:
Net earnings	2,853	[1]	1,681	[2]
Earnings from consolidated entities	0	[1]	0	[2]
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	0	[1]	0	[2]
Amortization of deferred policy acquisition costs	0	[3]	0	[4]
Change in allowance for losses on trade receivables	0	[1]	0	[2]
Change in allowance for inventory reserves	0	[1]	0	[2]
Net of (gains) losses on sale of real and personal property	0	[1]	0	[2]
Net (gain) loss on sale of investments	(258)	[1]	12	[2]
Deferred income tax	875	[1]	(236)	[2]
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	520	[1]	38,152	[2]
Inventories	0	[1]	0	[2]
Prepaid expenses	0	[1]	0	[2]
Capitalization of deferred policy acquisition costs	0	[1]	0	[2]
Other assets	190	[1]	1,164	[2]
Related party assets	(96)	[1]	(222)	[2]
Accounts payable and accrued expenses	0	[1]	0	[2]
Policy benefits and losses, claims and loss expenses payable	1,326	[1]	(42,772)	[2]
Other policyholders' funds and liabilities	(501)	[1]	(703)	[2]
Deferred income	0	[1]	0	[2]
Related party liabilities	467	[1]	105	[2]
Net cash provided by operating activities	5,376	[1]	(2,819)	[2]
Purchase of:
Property, plant and equipment	0	[1]	0	[2]
Short term investments	(16,298)	[1]	(22,430)	[2]
Fixed maturities investments	(14,285)	[1]	(9,576)	[2]
Equity securities	(388)	[1]
Preferred stock	(634)	[1]
Real estate	0	[1]
Mortgage loans	0	[1]	(1,821)	[2]
Proceeds from sale of:
Property, plant and equipment	0	[1]	0	[2]
Short term investments	14,570	[1]	12,706	[2]
Fixed maturities investments	5,213	[1]	12,983	[2]
Equity securities	388	[1]
Preferred stock	2,295	[1]	1,003	[2]
Real estate	0	[1]	0	[2]
Mortgage loans	221	[1]	577	[2]
Net cash used by investing activities	(8,918)	[1]	(6,558)	[2]
Cash flow from financing activities:
Borrowings from credit facilities	0	[1]	0	[2]
Principal repayments on credit facilities	0	[1]	0	[2]
Debt issuance costs	0	[1]
Capital lease payments	0	[1]	0	[2]
Leveraged Employee Stock Ownership Plan - repayments from loan	0	[1]	0	[2]
Securitization deposits	0	[1]	0	[2]
Proceeds from (repayment of) intercompany loans	0	[1]	0	[2]
Investment contract deposits	0	[1]	0	[2]
Investment contract withdrawals	0	[1]	0	[2]
Net cash used by financing activities	0	[1]	0	[2]
Effects of exchange rate on cash	0	[1]	0	[2]
Increase (decrease) in cash and cash equivalents	(3,542)	[1]	(9,377)	[2]
Cash and cash equivalents at the beginning of period	14,120	[5]	22,542	[2]
Cash and cash equivalents at the end of the period	10,578	[6]	13,165	[2]
Operating Segments | Life Insurance
Cash flow from operating activities:
Net earnings	2,655	[1]	901	[2]
Earnings from consolidated entities	0	[1]	0	[2]
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	0	[1]	0	[2]
Amortization of deferred policy acquisition costs	3,683	[3]	2,811	[4]
Change in allowance for losses on trade receivables	0	[1]	0	[2]
Change in allowance for inventory reserves	0	[1]	0	[2]
Net of (gains) losses on sale of real and personal property	0	[1]	0	[2]
Net (gain) loss on sale of investments	(1,512)	[1]	27	[2]
Deferred income tax	3,129	[1]	478	[2]
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	(2,154)	[1]	(2,250)	[2]
Inventories	0	[1]	0	[2]
Prepaid expenses	25	[1]	0	[2]
Capitalization of deferred policy acquisition costs	(7,808)	[1]	(5,420)	[2]
Other assets	(83)	[1]	(39)	[2]
Related party assets	0	[1]	(32)	[2]
Accounts payable and accrued expenses	(745)	[1]	(645)	[2]
Policy benefits and losses, claims and loss expenses payable	5,873	[1]	11,753	[2]
Other policyholders' funds and liabilities	321	[1]	(1,181)	[2]
Deferred income	0	[1]	0	[2]
Related party liabilities	233	[1]	(21)	[2]
Net cash provided by operating activities	3,617	[1]	6,382	[2]
Purchase of:
Property, plant and equipment	0	[1]	0	[2]
Short term investments	(48,354)	[1]	(37,965)	[2]
Fixed maturities investments	(52,570)	[1]	(40,977)	[2]
Equity securities	0	[1]
Preferred stock	0	[1]
Real estate	(131)	[1]
Mortgage loans	(5,785)	[1]	0	[2]
Proceeds from sale of:
Property, plant and equipment	0	[1]	0	[2]
Short term investments	50,248	[1]	46,715	[2]
Fixed maturities investments	36,278	[1]	10,995	[2]
Equity securities	0	[1]
Preferred stock	1,000	[1]	0	[2]
Real estate	0	[1]	4	[2]
Mortgage loans	852	[1]	1,868	[2]
Net cash used by investing activities	(18,462)	[1]	(19,360)	[2]
Cash flow from financing activities:
Borrowings from credit facilities	0	[1]	0	[2]
Principal repayments on credit facilities	0	[1]	0	[2]
Debt issuance costs	0	[1]
Capital lease payments	0	[1]	0	[2]
Leveraged Employee Stock Ownership Plan - repayments from loan	0	[1]	0	[2]
Securitization deposits	0	[1]	0	[2]
Proceeds from (repayment of) intercompany loans	0	[1]	0	[2]
Investment contract deposits	34,742	[1]	28,993	[2]
Investment contract withdrawals	(6,754)	[1]	(7,967)	[2]
Net cash used by financing activities	27,988	[1]	21,026	[2]
Effects of exchange rate on cash	0	[1]	0	[2]
Increase (decrease) in cash and cash equivalents	13,143	[1]	8,048	[2]
Cash and cash equivalents at the beginning of period	22,064	[5]	25,410	[2]
Cash and cash equivalents at the end of the period	35,207	[6]	33,458	[2]
Operating Segments | Moving and Storage Operating Segment
Cash flow from operating activities:
Net earnings	112,968		80,569
Earnings from consolidated entities	(5,508)		(2,582)
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	68,999		63,641
Amortization of deferred policy acquisition costs	0		0
Change in allowance for losses on trade receivables	(14)		(102)
Change in allowance for inventory reserves	(935)		695
Net of (gains) losses on sale of real and personal property	(11,565)		(7,516)
Net (gain) loss on sale of investments	(6)		0
Deferred income tax	27,824		4,399
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	(21,081)		(12,416)
Inventories	(973)		(5,398)
Prepaid expenses	14,073		267
Capitalization of deferred policy acquisition costs	0		0
Other assets	(4,639)		19,393
Related party assets	24,765		145,061
Accounts payable and accrued expenses	18,907		48,626
Policy benefits and losses, claims and loss expenses payable	(5,590)		6,777
Other policyholders' funds and liabilities	0		0
Deferred income	7,584		6,457
Related party liabilities	5,471		1,447
Net cash provided by operating activities	230,280		349,318
Purchase of:
Property, plant and equipment	(275,156)		(157,786)
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0
Preferred stock	0
Real estate	0
Mortgage loans	(5,566)		(12,631)
Proceeds from sale of:
Property, plant and equipment	93,239		62,426
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	516
Preferred stock	0		0
Real estate	0		0
Mortgage loans	20,632		9,102
Net cash used by investing activities	(166,335)		(98,889)
Cash flow from financing activities:
Borrowings from credit facilities	88,182		26,187
Principal repayments on credit facilities	(61,996)		(61,142)
Debt issuance costs	(232)
Capital lease payments	(10,449)		(3,888)
Leveraged Employee Stock Ownership Plan - repayments from loan	127		162
Securitization deposits	0		(908)
Proceeds from (repayment of) intercompany loans	0		0
Investment contract deposits	0		0
Investment contract withdrawals	0		0
Net cash used by financing activities	15,632		(39,589)
Effects of exchange rate on cash	(335)		(376)
Increase (decrease) in cash and cash equivalents	79,242		210,464
Cash and cash equivalents at the beginning of period	427,560		309,228
Cash and cash equivalents at the end of the period	506,802		519,692
Operating Segments | Moving and Storage Operating Segment | AMERCO
Cash flow from operating activities:
Net earnings	112,968		80,569
Earnings from consolidated entities	(99,795)		(66,615)
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	1		1
Amortization of deferred policy acquisition costs	0		0
Change in allowance for losses on trade receivables	0		0
Change in allowance for inventory reserves	0		0
Net of (gains) losses on sale of real and personal property	0		0
Net (gain) loss on sale of investments	(6)		0
Deferred income tax	27,824		4,399
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	0		0
Inventories	0		0
Prepaid expenses	22,475		9,496
Capitalization of deferred policy acquisition costs	0		0
Other assets	0		3
Related party assets	552		(1,488)
Accounts payable and accrued expenses	8,633		27,709
Policy benefits and losses, claims and loss expenses payable	0		0
Other policyholders' funds and liabilities	0		0
Deferred income	0		0
Related party liabilities	0		0
Net cash provided by operating activities	72,652		54,074
Purchase of:
Property, plant and equipment	0		0
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0
Preferred stock	0
Real estate	0
Mortgage loans	0		0
Proceeds from sale of:
Property, plant and equipment	0		0
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	516
Preferred stock	0		0
Real estate	0		0
Mortgage loans	0		0
Net cash used by investing activities	516		0
Cash flow from financing activities:
Borrowings from credit facilities	0		0
Principal repayments on credit facilities	0		0
Debt issuance costs	0
Capital lease payments	0		0
Leveraged Employee Stock Ownership Plan - repayments from loan	0		0
Securitization deposits	0		0
Proceeds from (repayment of) intercompany loans	(28,668)		(55,326)
Investment contract deposits	0		0
Investment contract withdrawals	0		0
Net cash used by financing activities	(28,668)		(55,326)
Effects of exchange rate on cash	0		0
Increase (decrease) in cash and cash equivalents	44,500		(1,252)
Cash and cash equivalents at the beginning of period	327,119		201,502
Cash and cash equivalents at the end of the period	371,619		200,250
Operating Segments | Moving and Storage Operating Segment | U-Haul
Cash flow from operating activities:
Net earnings	92,049		63,331
Earnings from consolidated entities	0		0
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	65,055		59,836
Amortization of deferred policy acquisition costs	0		0
Change in allowance for losses on trade receivables	(14)		(102)
Change in allowance for inventory reserves	(935)		695
Net of (gains) losses on sale of real and personal property	(10,889)		(7,516)
Net (gain) loss on sale of investments	0		0
Deferred income tax	0		0
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	(21,081)		(12,416)
Inventories	(973)		(5,398)
Prepaid expenses	(7,723)		(9,063)
Capitalization of deferred policy acquisition costs	0		0
Other assets	(1,172)		19,649
Related party assets	24,213		146,547
Accounts payable and accrued expenses	10,400		20,736
Policy benefits and losses, claims and loss expenses payable	(5,590)		6,777
Other policyholders' funds and liabilities	0		0
Deferred income	7,584		6,457
Related party liabilities	1,158		1,447
Net cash provided by operating activities	152,082		290,980
Purchase of:
Property, plant and equipment	(156,306)		(131,874)
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0
Preferred stock	0
Real estate	0
Mortgage loans	(1,580)		(5,048)
Proceeds from sale of:
Property, plant and equipment	92,112		62,426
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	1,680		8,029
Net cash used by investing activities	(64,094)		(66,467)
Cash flow from financing activities:
Borrowings from credit facilities	39,258		26,187
Principal repayments on credit facilities	(29,295)		(55,254)
Debt issuance costs	(177)
Capital lease payments	(10,449)		(3,888)
Leveraged Employee Stock Ownership Plan - repayments from loan	127		162
Securitization deposits	0		(908)
Proceeds from (repayment of) intercompany loans	(52,359)		21,300
Investment contract deposits	0		0
Investment contract withdrawals	0		0
Net cash used by financing activities	(52,895)		(12,401)
Effects of exchange rate on cash	(335)		(376)
Increase (decrease) in cash and cash equivalents	34,758		211,736
Cash and cash equivalents at the beginning of period	98,926		106,951
Cash and cash equivalents at the end of the period	133,684		318,687
Operating Segments | Moving and Storage Operating Segment | Real Estate
Cash flow from operating activities:
Net earnings	2,238		702
Earnings from consolidated entities	0		0
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	3,943		3,804
Amortization of deferred policy acquisition costs	0		0
Change in allowance for losses on trade receivables	0		0
Change in allowance for inventory reserves	0		0
Net of (gains) losses on sale of real and personal property	(676)		0
Net (gain) loss on sale of investments	0		0
Deferred income tax	0		0
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	0		0
Inventories	0		0
Prepaid expenses	(679)		(166)
Capitalization of deferred policy acquisition costs	0		0
Other assets	(3,467)		(259)
Related party assets	0		2
Accounts payable and accrued expenses	(126)		181
Policy benefits and losses, claims and loss expenses payable	0		0
Other policyholders' funds and liabilities	0		0
Deferred income	0		0
Related party liabilities	4,313		0
Net cash provided by operating activities	5,546		4,264
Purchase of:
Property, plant and equipment	(118,850)		(25,912)
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0
Preferred stock	0
Real estate	0
Mortgage loans	(6,500)		(7,583)
Proceeds from sale of:
Property, plant and equipment	1,127		0
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	21,466		1,073
Net cash used by investing activities	(102,757)		(32,422)
Cash flow from financing activities:
Borrowings from credit facilities	48,924		0
Principal repayments on credit facilities	(32,701)		(5,888)
Debt issuance costs	(55)
Capital lease payments	0		0
Leveraged Employee Stock Ownership Plan - repayments from loan	0		0
Securitization deposits	0		0
Proceeds from (repayment of) intercompany loans	81,027		34,026
Investment contract deposits	0		0
Investment contract withdrawals	0		0
Net cash used by financing activities	97,195		28,138
Effects of exchange rate on cash	0		0
Increase (decrease) in cash and cash equivalents	(16)		(20)
Cash and cash equivalents at the beginning of period	1,515		775
Cash and cash equivalents at the end of the period	1,499		755
Operating Segments | Moving and Storage Operating Segment | Moving and Storage Operating Eliminations
Cash flow from operating activities:
Net earnings	(94,287)		(64,033)
Earnings from consolidated entities	94,287		64,033
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	0		0
Amortization of deferred policy acquisition costs	0		0
Change in allowance for losses on trade receivables	0		0
Change in allowance for inventory reserves	0		0
Net of (gains) losses on sale of real and personal property	0		0
Net (gain) loss on sale of investments	0		0
Deferred income tax	0		0
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	0		0
Inventories	0		0
Prepaid expenses	0		0
Capitalization of deferred policy acquisition costs	0		0
Other assets	0		0
Related party assets	0		0
Accounts payable and accrued expenses	0		0
Policy benefits and losses, claims and loss expenses payable	0		0
Other policyholders' funds and liabilities	0		0
Deferred income	0		0
Related party liabilities	0		0
Net cash provided by operating activities	0		0
Purchase of:
Property, plant and equipment	0		0
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0
Preferred stock	0
Real estate	0
Mortgage loans	2,514		0
Proceeds from sale of:
Property, plant and equipment	0		0
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	(2,514)		0
Net cash used by investing activities	0		0
Cash flow from financing activities:
Borrowings from credit facilities	0		0
Principal repayments on credit facilities	0		0
Debt issuance costs	0
Capital lease payments	0		0
Leveraged Employee Stock Ownership Plan - repayments from loan	0		0
Securitization deposits	0		0
Proceeds from (repayment of) intercompany loans	0		0
Investment contract deposits	0		0
Investment contract withdrawals	0		0
Net cash used by financing activities	0		0
Effects of exchange rate on cash	0		0
Increase (decrease) in cash and cash equivalents	0		0
Cash and cash equivalents at the beginning of period	0		0
Cash and cash equivalents at the end of the period	0		0
Eliminations
Cash flow from operating activities:
Net earnings	(5,508)		(2,582)
Earnings from consolidated entities	5,508		2,582
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	0		0
Amortization of deferred policy acquisition costs	0		0
Change in allowance for losses on trade receivables	0		0
Change in allowance for inventory reserves	0		0
Net of (gains) losses on sale of real and personal property	0		0
Net (gain) loss on sale of investments	0		0
Deferred income tax	0		0
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	0		0
Inventories	0		0
Prepaid expenses	0		0
Capitalization of deferred policy acquisition costs	0		0
Other assets	0		0
Related party assets	209	[7]	83	[7]
Accounts payable and accrued expenses	0		0
Policy benefits and losses, claims and loss expenses payable	0		0
Other policyholders' funds and liabilities	0		0
Deferred income	0		0
Related party liabilities	(209)	[7]	(83)	[7]
Net cash provided by operating activities	0		0
Purchase of:
Property, plant and equipment	0		0
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0
Preferred stock	0
Real estate	0
Mortgage loans	(1,553)	[7]	0
Proceeds from sale of:
Property, plant and equipment	0		0
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	1,553	[7]	0
Net cash used by investing activities	0		0
Cash flow from financing activities:
Borrowings from credit facilities	0		0
Principal repayments on credit facilities	0		0
Debt issuance costs	0
Capital lease payments	0		0
Leveraged Employee Stock Ownership Plan - repayments from loan	0		0
Securitization deposits	0		0
Proceeds from (repayment of) intercompany loans	0		0
Investment contract deposits	0		0
Investment contract withdrawals	0		0
Net cash used by financing activities	0		0
Effects of exchange rate on cash	0		0
Increase (decrease) in cash and cash equivalents	0		0
Cash and cash equivalents at the beginning of period	0		0
Cash and cash equivalents at the end of the period	$ 0		$ 0

[1] Balance for the period ended March 31, 2013

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

[3] Balances for the quarter ended March 31, 2013

[4] Balance for the quarter ended March 31, 2012

[5] Balances as of December 31, 2012

[6] Balances as of March 31, 2013

[7] Elimination of intercompany investments