Consolidated Cash Flow Statement by Industry Segment (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Sep. 30, 2013		Sep. 30, 2012
Cash flow from operating activities:
Net earnings	$ 250,959		$ 189,989
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	141,518		128,127
Amortization of deferred policy acquisition costs	9,740		5,899
Change in allowance for losses on trade receivables	(6)		(3)
Change in allowance for inventory reserves	716		1,705
Net gain on sale of real and personal property	(20,876)		(13,048)
Net gain on sale of investments	(4,060)		238
Deferred income taxes	63,947		24,926
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	24,561		33,416
Inventories	(5,750)		(1,629)
Prepaid expenses	2,323		422
Capitalization of deferred policy acquisition costs	(16,289)		(24,489)
Other assets	(4,370)		19,770
Related party assets	8,650		142,239
Accounts payable and accrued expenses	24,866		45,412
Policy benefits and losses, claims and loss expenses payable	309		(17,413)
Other policyholders' funds and liabilities	494		4,130
Deferred income	2,191		(671)
Related party liabilities	4,475		415
Net cash provided by operating activities	483,398		539,435
Purchases of:
Property, plant and equipment	(457,671)		(280,986)
Short term investments	(154,703)		(150,987)
Fixed maturities investments	(174,593)		(179,941)
Equity securities	(388)		(26)
Preferred stock	(635)		(1,200)
Real estate	(252)		(792)
Mortgage loans	(14,260)		(50,828)
Proceeds from sale and paydowns of:
Property, plant and equipment	176,453		132,597
Short term investments	162,580		154,577
Fixed maturities investments	93,050		52,586
Equity securities	6,803		0
Preferred stock	6,004		1,453
Real estate	0		590
Mortgage loans	36,415		12,700
Net cash used by investing activities	(321,197)		(310,257)
Cash flow from financing activities:
Borrowings from credit facilities	138,041		88,847
Principal repayments on credit facilities	(122,945)		(171,496)
Debt issuance costs	(233)		(1,010)
Capital lease payments	(21,425)		(9,883)
Leveraged Employee Stock Ownership Plan - repayments from loan	260		316
Securitization deposits	0		(1,729)
Proceeds from (repayment of) intercompany loans	0		0
Investment contract deposits	74,253		169,933
Investment contract withdrawals	(14,721)		(15,275)
Net cash (used) by financing activities	53,230		59,703
Effects of exchange rate on cash	401		(240)
Increase in cash and cash equivalents	215,832		288,641
Cash and cash equivalents at the beginning of period	463,744		357,180
Cash and cash equivalents at the end of the period	679,576		645,821
Operating Segments | Property and Casualty Insurance
Cash flow from operating activities:
Net earnings	7,021	[1]	3,204	[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	[1]	0	[2]
Change in allowance for losses on trade receivables	0	[1]	0	[2]
Change in allowance for inventory reserves	0	[1]	0	[2]
Net gain on sale of real and personal property	0	[1]	0	[2]
Net gain on sale of investments	(267)	[1]	(16)	[2]
Deferred income taxes	3,118	[1]	584	[2]
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	4,489	[1]	44,699	[2]
Inventories	0	[1]	0	[2]
Prepaid expenses	0	[1]	0	[2]
Capitalization of deferred policy acquisition costs	0	[1]	0	[2]
Other assets	309	[1]	914	[2]
Related party assets	(5,584)	[1]	(1,748)	[2]
Accounts payable and accrued expenses	0	[1]	0	[2]
Policy benefits and losses, claims and loss expenses payable	(7,009)	[1]	(47,835)	[2]
Other policyholders' funds and liabilities	76	[1]	(310)	[2]
Deferred income	0	[1]	0	[2]
Related party liabilities	(57)	[1]	245	[2]
Net cash provided by operating activities	2,096	[1]	(263)	[2]
Purchases of:
Property, plant and equipment	0	[1]	0	[2]
Short term investments	(27,972)	[1]	(37,553)	[2]
Fixed maturities investments	(39,655)	[1]	(10,316)	[2]
Equity securities	(388)	[1]	(26)	[2]
Preferred stock	(635)	[1]	(1,200)	[2]
Real estate	0	[1]	0	[2]
Mortgage loans	0	[1]	(1,821)	[2]
Proceeds from sale and paydowns of:
Property, plant and equipment	0	[1]	0	[2]
Short term investments	39,072	[1]	22,174	[2]
Fixed maturities investments	11,936	[1]	23,662	[2]
Equity securities	388	[1]
Preferred stock	4,504	[1]	1,453	[2]
Real estate	0	[1]	0	[2]
Mortgage loans	1,984	[1]	939	[2]
Net cash used by investing activities	(10,766)	[1]	(2,688)	[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]	0	[2]
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]
Net contribution from (to) related party			1,500	[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]	1,500	[2]
Effects of exchange rate on cash	0	[1]	0	[2]
Increase in cash and cash equivalents	(8,670)	[1]	(1,451)	[2]
Cash and cash equivalents at the beginning of period	14,120	[1],[3]	22,542	[2]
Cash and cash equivalents at the end of the period	5,450	[1],[4]	21,091	[2]
Operating Segments | Life Insurance
Cash flow from operating activities:
Net earnings	7,562	[1]	4,063	[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	9,740	[1]	5,899	[2]
Change in allowance for losses on trade receivables	0	[1]	0	[2]
Change in allowance for inventory reserves	0	[1]	0	[2]
Net gain on sale of real and personal property	0	[1]	0	[2]
Net gain on sale of investments	(3,751)	[1]	254	[2]
Deferred income taxes	2,157	[1]	(3,557)	[2]
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	3,961	[1]	(2)	[2]
Inventories	0	[1]	0	[2]
Prepaid expenses	0	[1]	0	[2]
Capitalization of deferred policy acquisition costs	(16,289)	[1]	(24,489)	[2]
Other assets	(74)	[1]	(24)	[2]
Related party assets	0	[1]	(28)	[2]
Accounts payable and accrued expenses	2,971	[1]	11,565	[2]
Policy benefits and losses, claims and loss expenses payable	5,831	[1]	18,450	[2]
Other policyholders' funds and liabilities	418	[1]	4,440	[2]
Deferred income	0	[1]	0	[2]
Related party liabilities	(71)	[1]	43	[2]
Net cash provided by operating activities	12,455	[1]	16,614	[2]
Purchases of:
Property, plant and equipment	0	[1]	0	[2]
Short term investments	(126,731)	[1]	(113,434)	[2]
Fixed maturities investments	(134,938)	[1]	(169,625)	[2]
Equity securities	0	[1]	0	[2]
Preferred stock	0	[1]	0	[2]
Real estate	(252)	[1]	(792)	[2]
Mortgage loans	(14,009)	[1]	(13,204)	[2]
Proceeds from sale and paydowns of:
Property, plant and equipment	0	[1]	0	[2]
Short term investments	123,508	[1]	132,403	[2]
Fixed maturities investments	81,114	[1]	28,924	[2]
Equity securities	0	[1]
Preferred stock	1,500	[1]	0	[2]
Real estate	0	[1]	4	[2]
Mortgage loans	12,175	[1]	2,659	[2]
Net cash used by investing activities	(57,633)	[1]	(133,065)	[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]	0	[2]
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]
Net contribution from (to) related party			0	[2]
Proceeds from (repayment of) intercompany loans	0	[1]	0	[2]
Investment contract deposits	74,253	[1]	169,933	[2]
Investment contract withdrawals	(14,721)	[1]	(15,275)	[2]
Net cash (used) by financing activities	59,532	[1]	154,658	[2]
Effects of exchange rate on cash	0	[1]	0	[2]
Increase in cash and cash equivalents	14,354	[1]	38,207	[2]
Cash and cash equivalents at the beginning of period	22,064	[1],[3]	25,410	[2]
Cash and cash equivalents at the end of the period	36,418	[1],[4]	63,617	[2]
Operating Segments | Moving and Storage Operating Segment
Cash flow from operating activities:
Net earnings	250,959		189,989
Earnings from consolidated entities	(14,583)		(7,267)
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	141,518		128,127
Amortization of deferred policy acquisition costs	0		0
Change in allowance for losses on trade receivables	(6)		(3)
Change in allowance for inventory reserves	716		1,705
Net gain on sale of real and personal property	(20,876)		(13,048)
Net gain on sale of investments	(42)		0
Deferred income taxes	58,672		27,899
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	16,111		(11,281)
Inventories	(5,750)		(1,629)
Prepaid expenses	2,323		422
Capitalization of deferred policy acquisition costs	0		0
Other assets	(4,605)		18,880
Related party assets	14,085		143,175
Accounts payable and accrued expenses	21,895		33,847
Policy benefits and losses, claims and loss expenses payable	1,487		11,972
Other policyholders' funds and liabilities	0		0
Deferred income	2,191		(671)
Related party liabilities	4,752		967
Net cash provided by operating activities	468,847		523,084
Purchases of:
Property, plant and equipment	(457,671)		(280,986)
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0		0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	(11,804)		(35,803)
Proceeds from sale and paydowns of:
Property, plant and equipment	176,453		132,597
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	6,415
Preferred stock	0		0
Real estate	0		586
Mortgage loans	33,809		9,102
Net cash used by investing activities	(252,798)		(174,504)
Cash flow from financing activities:
Borrowings from credit facilities	138,041		88,847
Principal repayments on credit facilities	(122,945)		(171,496)
Debt issuance costs	(233)		(1,010)
Capital lease payments	(21,425)		(9,883)
Leveraged Employee Stock Ownership Plan - repayments from loan	260		316
Securitization deposits	0		(1,729)
Net contribution from (to) related party			(1,500)
Proceeds from (repayment of) intercompany loans	0		0
Investment contract deposits	0		0
Investment contract withdrawals	0		0
Net cash (used) by financing activities	(6,302)		(96,455)
Effects of exchange rate on cash	401		(240)
Increase in cash and cash equivalents	210,148		251,885
Cash and cash equivalents at the beginning of period	427,560		309,228
Cash and cash equivalents at the end of the period	637,708		561,113
Operating Segments | Moving and Storage Operating Segment | AMERCO
Cash flow from operating activities:
Net earnings	250,959		189,989
Earnings from consolidated entities	(224,946)		(164,124)
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	3		3
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 gain on sale of real and personal property	0		0
Net gain on sale of investments	(42)		0
Deferred income taxes	58,672		27,899
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	0		0
Inventories	0		0
Prepaid expenses	11,178		7,558
Capitalization of deferred policy acquisition costs	0		0
Other assets	5		3
Related party assets	551		12
Accounts payable and accrued expenses	3,699		2,045
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	100,079		63,385
Purchases of:
Property, plant and equipment	0		(2)
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0		0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	0		0
Proceeds from sale and paydowns of:
Property, plant and equipment	0		0
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	6,415
Preferred stock	0		0
Real estate	0		0
Mortgage loans	0		0
Net cash used by investing activities	6,415		(2)
Cash flow from financing activities:
Borrowings from credit facilities	0		0
Principal repayments on credit facilities	0		0
Debt issuance costs	0		0
Capital lease payments	0		0
Leveraged Employee Stock Ownership Plan - repayments from loan	0		0
Securitization deposits	0		0
Net contribution from (to) related party			(1,500)
Proceeds from (repayment of) intercompany loans	43,946		163,363
Investment contract deposits	0		0
Investment contract withdrawals	0		0
Net cash (used) by financing activities	43,946		161,863
Effects of exchange rate on cash	0		0
Increase in cash and cash equivalents	150,440		225,246
Cash and cash equivalents at the beginning of period	327,119		201,502
Cash and cash equivalents at the end of the period	477,559		426,748
Operating Segments | Moving and Storage Operating Segment | U-Haul
Cash flow from operating activities:
Net earnings	207,460		154,913
Earnings from consolidated entities	0		0
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	133,101		120,651
Amortization of deferred policy acquisition costs	0		0
Change in allowance for losses on trade receivables	(6)		(3)
Change in allowance for inventory reserves	716		1,705
Net gain on sale of real and personal property	(20,200)		(12,771)
Net gain on sale of investments	0		0
Deferred income taxes	0		0
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	16,288		(11,281)
Inventories	(5,750)		(1,629)
Prepaid expenses	(8,077)		(6,910)
Capitalization of deferred policy acquisition costs	0		0
Other assets	(378)		20,161
Related party assets	13,534		143,163
Accounts payable and accrued expenses	18,288		31,336
Policy benefits and losses, claims and loss expenses payable	1,487		11,972
Other policyholders' funds and liabilities	0		0
Deferred income	2,191		(671)
Related party liabilities	460		967
Net cash provided by operating activities	359,114		451,603
Purchases of:
Property, plant and equipment	(295,231)		(240,045)
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0		0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	(1,580)		(5,016)
Proceeds from sale and paydowns of:
Property, plant and equipment	175,302		132,204
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	(119,829)		(104,828)
Cash flow from financing activities:
Borrowings from credit facilities	64,124		27,147
Principal repayments on credit facilities	(58,684)		(110,799)
Debt issuance costs	(178)		(20)
Capital lease payments	(21,425)		(9,883)
Leveraged Employee Stock Ownership Plan - repayments from loan	260		316
Securitization deposits	0		(1,729)
Net contribution from (to) related party			0
Proceeds from (repayment of) intercompany loans	(164,059)		(225,651)
Investment contract deposits	0		0
Investment contract withdrawals	0		0
Net cash (used) by financing activities	(179,962)		(320,619)
Effects of exchange rate on cash	401		(240)
Increase in cash and cash equivalents	59,724		25,916
Cash and cash equivalents at the beginning of period	98,926		106,951
Cash and cash equivalents at the end of the period	158,650		132,867
Operating Segments | Moving and Storage Operating Segment | Real Estate
Cash flow from operating activities:
Net earnings	2,903		1,944
Earnings from consolidated entities	0		0
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	8,414		7,473
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 gain on sale of real and personal property	(676)		(277)
Net gain on sale of investments	0		0
Deferred income taxes	0		0
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	(177)		0
Inventories	0		0
Prepaid expenses	(778)		(226)
Capitalization of deferred policy acquisition costs	0		0
Other assets	(4,232)		(1,284)
Related party assets	0		0
Accounts payable and accrued expenses	(92)		466
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	4,292		0
Net cash provided by operating activities	9,654		8,096
Purchases of:
Property, plant and equipment	(162,440)		(40,939)
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0		0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	(12,738)		(30,787)
Proceeds from sale and paydowns of:
Property, plant and equipment	1,151		393
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0
Preferred stock	0		0
Real estate	0		586
Mortgage loans	34,643		1,073
Net cash used by investing activities	(139,384)		(69,674)
Cash flow from financing activities:
Borrowings from credit facilities	73,917		61,700
Principal repayments on credit facilities	(64,261)		(60,697)
Debt issuance costs	(55)		(990)
Capital lease payments	0		0
Leveraged Employee Stock Ownership Plan - repayments from loan	0		0
Securitization deposits	0		0
Net contribution from (to) related party			0
Proceeds from (repayment of) intercompany loans	120,113		62,288
Investment contract deposits	0		0
Investment contract withdrawals	0		0
Net cash (used) by financing activities	129,714		62,301
Effects of exchange rate on cash	0		0
Increase in cash and cash equivalents	(16)		723
Cash and cash equivalents at the beginning of period	1,515		775
Cash and cash equivalents at the end of the period	1,499		1,498
Operating Segments | Moving and Storage Operating Segment | Moving and Storage Operating Eliminations
Cash flow from operating activities:
Net earnings	(210,363)		(156,857)
Earnings from consolidated entities	210,363		156,857
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 gain on sale of real and personal property	0		0
Net gain on sale of investments	0		0
Deferred income taxes	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
Purchases of:
Property, plant and equipment	0		0
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0		0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	2,514	[5]	0
Proceeds from sale and paydowns 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)	[5]	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		0
Capital lease payments	0		0
Leveraged Employee Stock Ownership Plan - repayments from loan	0		0
Securitization deposits	0		0
Net contribution from (to) related party			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 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	(14,583)		(7,267)
Earnings from consolidated entities	14,583		7,267
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 gain on sale of real and personal property	0		0
Net gain on sale of investments	0		0
Deferred income taxes	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	149	[5]	840	[5]
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	(149)	[5]	(840)	[5]
Net cash provided by operating activities	0		0
Purchases of:
Property, plant and equipment	0		0
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0		0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	11,553	[5]	0
Proceeds from sale and paydowns 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	(11,553)	[5]	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		0
Capital lease payments	0		0
Leveraged Employee Stock Ownership Plan - repayments from loan	0		0
Securitization deposits	0		0
Net contribution from (to) related party			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 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] Balances for the six months ended June 30, 2013

[2] Balances for the six months ended June 30, 2012

[3] Balances as of December 31, 2012

[4] Balances as of June 30, 2013

[5] Elimination of intercompany investments