Consolidated Cash Flow Statement by Industry Segment (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
Cash flow from operating activities:
Net earnings	$ 303,180		$ 226,835
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	214,268		192,357
Amortization of deferred policy acquisition costs	14,197		9,290
Change in allowance for losses on trade receivables	12		(73)
Change in allowance for inventory reserves	3,640		2,050
Net gain on sale of real and personal property	(22,837)		(14,879)
Net gain on sale of investments	(6,088)		(1,050)
Deferred income taxes	48,033		17,757
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	33,355		71,709
Inventories	(12,502)		696
Prepaid expenses	13,109		(13,283)
Capitalization of deferred policy acquisition costs	(25,128)		(43,085)
Other assets	7,929		22,712
Related party assets	5,630		139,590
Accounts payable and accrued expenses	(2,772)		(872)
Policy benefits and losses, claims and loss expenses payable	(18,337)		(30,226)
Other policyholders' funds and liabilities	(23)		(925)
Deferred income	(672)		(3,704)
Related party liabilities	6,257		1,388
Net cash provided by operating activities	561,251		576,287
Purchases of:
Property, plant and equipment	(690,293)		(422,840)
Short term investments	(203,763)		(289,773)
Fixed maturities investments	(237,502)		(308,290)
Equity securities	(388)		(3,130)
Preferred stock	(635)		(2,761)
Real estate	(431)		(1,053)
Mortgage loans	(48,632)		(50,583)
Proceeds from sale and paydowns of:
Property, plant and equipment	214,078		166,904
Short term investments	211,841		280,890
Fixed maturities investments	124,145		85,132
Equity securities	26,957		0
Preferred stock	6,004		5,728
Real estate	0		671
Mortgage loans	45,234		49,215
Net cash used by investing activities	(553,385)		(489,890)
Cash flow from financing activities:
Borrowings from credit facilities	323,039		251,319
Principal repayments on credit facilities	(238,553)		(234,698)
Debt issuance costs	(3,353)		(2,352)
Capital lease payments	(37,480)		(18,310)
Leveraged Employee Stock Ownership Plan - repayments from loan	390		559
Securitization deposits	0		(1,729)
Common stock dividends paid	0		(97,421)
Proceeds from (repayment of) intercompany loans	0		0
Investment contract deposits	109,928		268,478
Investment contract withdrawals	(24,448)		(22,937)
Net cash provided by financing activities	129,523		142,909
Effects of exchange rate on cash	482		(362)
Increase in cash and cash equivalents	137,871		228,944
Cash and cash equivalents at the beginning of period	463,744		357,180
Cash and cash equivalents at the end of the period	601,615		586,124
Operating Segments | Property and Casualty Insurance
Cash flow from operating activities:
Net earnings	10,737	[1]	4,544	[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 gain on sale of real and personal property	0	[1]	0	[2]
Net gain on sale of investments	(674)	[1]	28	[2]
Deferred income taxes	5,118	[1]	1,306	[2]
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	23,296	[1]	58,841	[2]
Inventories	0	[1]	0	[2]
Prepaid expenses	0	[1]	0	[2]
Capitalization of deferred policy acquisition costs	0	[1]	0	[2]
Other assets	201	[1]	1,018	[2]
Related party assets	(4,702)	[1]	(1,202)	[2]
Accounts payable and accrued expenses	0	[1]	0	[2]
Policy benefits and losses, claims and loss expenses payable	(29,833)	[1]	(60,391)	[2]
Other policyholders' funds and liabilities	(39)	[1]	(585)	[2]
Deferred income	0	[1]	0	[2]
Related party liabilities	2,850	[1]	632	[2]
Net cash provided by operating activities	6,954	[1]	4,191	[2]
Purchases of:
Property, plant and equipment	0	[1]	0	[2]
Short term investments	(35,250)	[1]	(58,775)	[2]
Fixed maturities investments	(50,840)	[1]	(17,141)	[2]
Equity securities	(388)	[1]	(3,130)	[2]
Preferred stock	(635)	[1]	(2,761)	[2]
Real estate	0	[1]	0	[2]
Mortgage loans	(3,500)	[1]	(1,821)	[2]
Proceeds from sale and paydowns of:
Property, plant and equipment	0	[1]	0	[2]
Short term investments	50,044	[1]	32,548	[2]
Fixed maturities investments	14,892	[1]	30,298	[2]
Equity securities	388	[1]	0	[2]
Preferred stock	4,504	[1]	5,728	[2]
Real estate	0	[1]	0	[2]
Mortgage loans	5,312	[1]	1,311	[2]
Net cash used by investing activities	(15,473)	[1]	(13,743)	[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]
Common stock dividends paid			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 provided by financing activities	0	[1]	1,500	[2]
Effects of exchange rate on cash	0	[1]	0	[2]
Increase in cash and cash equivalents	(8,519)	[1]	(8,052)	[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	5,601	[6]	14,490	[2]
Operating Segments | Life Insurance
Cash flow from operating activities:
Net earnings	13,127	[1]	8,368	[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	14,197	[3]	9,290	[4]
Change in allowance for losses on trade receivables	9	[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	(4,089)	[1]	(1,078)	[2]
Deferred income taxes	4,981	[1]	(1,431)	[2]
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	(3,174)	[1]	575	[2]
Inventories	0	[1]	0	[2]
Prepaid expenses	0	[1]	0	[2]
Capitalization of deferred policy acquisition costs	(25,128)	[1]	(43,085)	[2]
Other assets	(120)	[1]	(11)	[2]
Related party assets	0	[1]	(34)	[2]
Accounts payable and accrued expenses	13,218	[1]	(3,196)	[2]
Policy benefits and losses, claims and loss expenses payable	10,278	[1]	21,684	[2]
Other policyholders' funds and liabilities	16	[1]	(340)	[2]
Deferred income	0	[1]	0	[2]
Related party liabilities	303	[1]	483	[2]
Net cash provided by operating activities	23,618	[1]	(8,775)	[2]
Purchases of:
Property, plant and equipment	0	[1]	0	[2]
Short term investments	(168,513)	[1]	(230,998)	[2]
Fixed maturities investments	(186,662)	[1]	(291,149)	[2]
Equity securities	0	[1]	0	[2]
Preferred stock	0	[1]	0	[2]
Real estate	(431)	[1]	(810)	[2]
Mortgage loans	(37,459)	[1]	(13,204)	[2]
Proceeds from sale and paydowns of:
Property, plant and equipment	0	[1]	0	[2]
Short term investments	161,797	[1]	248,342	[2]
Fixed maturities investments	109,253	[1]	54,834	[2]
Equity securities	0	[1]	0	[2]
Preferred stock	1,500	[1]	0	[2]
Real estate	0	[1]	4	[2]
Mortgage loans	13,947	[1]	3,556	[2]
Net cash used by investing activities	(106,568)	[1]	(229,425)	[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]
Common stock dividends paid			0	[2]
Net contribution from (to) related party			0	[2]
Proceeds from (repayment of) intercompany loans	0	[1]	0	[2]
Investment contract deposits	109,928	[1]	268,478	[2]
Investment contract withdrawals	(24,448)	[1]	(22,937)	[2]
Net cash provided by financing activities	85,480	[1]	245,541	[2]
Effects of exchange rate on cash	0	[1]	0	[2]
Increase in cash and cash equivalents	2,530	[1]	7,341	[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	24,594	[6]	32,751	[2]
Operating Segments | Moving and Storage Operating Segment
Cash flow from operating activities:
Net earnings	303,180		226,835
Earnings from consolidated entities	(23,864)		(12,912)
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	214,268		192,357
Amortization of deferred policy acquisition costs	0		0
Change in allowance for losses on trade receivables	3		(73)
Change in allowance for inventory reserves	3,640		2,050
Net gain on sale of real and personal property	(22,837)		(14,879)
Net gain on sale of investments	(1,325)		0
Deferred income taxes	37,934		17,882
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	13,233		12,293
Inventories	(12,502)		696
Prepaid expenses	13,109		(13,283)
Capitalization of deferred policy acquisition costs	0		0
Other assets	7,848		21,705
Related party assets	10,173		140,035
Accounts payable and accrued expenses	(15,990)		2,324
Policy benefits and losses, claims and loss expenses payable	1,218		8,481
Other policyholders' funds and liabilities	0		0
Deferred income	(672)		(3,704)
Related party liabilities	3,263		1,064
Net cash provided by operating activities	530,679		580,871
Purchases of:
Property, plant and equipment	(690,293)		(422,840)
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0		0
Preferred stock	0		0
Real estate	0		(243)
Mortgage loans	(19,262)		(35,558)
Proceeds from sale and paydowns of:
Property, plant and equipment	214,078		166,904
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	26,569		0
Preferred stock	0		0
Real estate	0		667
Mortgage loans	37,564		44,348
Net cash used by investing activities	(431,344)		(246,722)
Cash flow from financing activities:
Borrowings from credit facilities	323,039		251,319
Principal repayments on credit facilities	(238,553)		(234,698)
Debt issuance costs	(3,353)		(2,352)
Capital lease payments	(37,480)		(18,310)
Leveraged Employee Stock Ownership Plan - repayments from loan	390		559
Securitization deposits	0		(1,729)
Common stock dividends paid			(97,421)
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 provided by financing activities	44,043		(104,132)
Effects of exchange rate on cash	482		(362)
Increase in cash and cash equivalents	143,860		229,655
Cash and cash equivalents at the beginning of period	427,560		309,228
Cash and cash equivalents at the end of the period	571,420		538,883
Operating Segments | Moving and Storage Operating Segment | AMERCO
Cash flow from operating activities:
Net earnings	303,180		226,835
Earnings from consolidated entities	(263,524)		(188,559)
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	4		4
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	(1,325)		0
Deferred income taxes	37,934		17,882
Net change in other operating assets and liabilities:
Reinsurance recoverables and trade receivables	0		0
Inventories	0		0
Prepaid expenses	22,475		(3,082)
Capitalization of deferred policy acquisition costs	0		0
Other assets	5		3
Related party assets	540		(2)
Accounts payable and accrued expenses	6,563		1,818
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	105,852		54,899
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	26,569		0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	0		0
Net cash used by investing activities	26,569		(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
Common stock dividends paid			(97,421)
Net contribution from (to) related party			(1,500)
Proceeds from (repayment of) intercompany loans	17,011		194,277
Investment contract deposits	0		0
Investment contract withdrawals	0		0
Net cash provided by financing activities	17,011		95,356
Effects of exchange rate on cash	0		0
Increase in cash and cash equivalents	149,432		150,253
Cash and cash equivalents at the beginning of period	327,119		201,502
Cash and cash equivalents at the end of the period	476,551		351,755
Operating Segments | Moving and Storage Operating Segment | U-Haul
Cash flow from operating activities:
Net earnings	235,997		169,442
Earnings from consolidated entities	0		0
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	201,286		181,084
Amortization of deferred policy acquisition costs	0		0
Change in allowance for losses on trade receivables	3		(73)
Change in allowance for inventory reserves	3,640		2,050
Net gain on sale of real and personal property	(22,045)		(13,075)
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	13,410		12,293
Inventories	(12,502)		696
Prepaid expenses	(8,660)		(9,972)
Capitalization of deferred policy acquisition costs	0		0
Other assets	10,558		22,271
Related party assets	9,636		140,035
Accounts payable and accrued expenses	(22,843)		(32)
Policy benefits and losses, claims and loss expenses payable	1,218		8,481
Other policyholders' funds and liabilities	0		0
Deferred income	(672)		(3,704)
Related party liabilities	(1,007)		1,064
Net cash provided by operating activities	408,019		510,560
Purchases of:
Property, plant and equipment	(436,671)		(351,914)
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)		(4,968)
Proceeds from sale and paydowns of:
Property, plant and equipment	212,601		161,668
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0		0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	1,680		14,848
Net cash used by investing activities	(223,970)		(180,366)
Cash flow from financing activities:
Borrowings from credit facilities	116,952		89,619
Principal repayments on credit facilities	(149,948)		(142,750)
Debt issuance costs	(641)		(301)
Capital lease payments	(37,480)		(18,310)
Leveraged Employee Stock Ownership Plan - repayments from loan	390		559
Securitization deposits	0		(1,729)
Common stock dividends paid			0
Net contribution from (to) related party			0
Proceeds from (repayment of) intercompany loans	(120,035)		(178,247)
Investment contract deposits	0		0
Investment contract withdrawals	0		0
Net cash provided by financing activities	(190,762)		(251,159)
Effects of exchange rate on cash	482		(362)
Increase in cash and cash equivalents	(6,231)		78,673
Cash and cash equivalents at the beginning of period	98,926		106,951
Cash and cash equivalents at the end of the period	92,695		185,624
Operating Segments | Moving and Storage Operating Segment | Real Estate
Cash flow from operating activities:
Net earnings	3,663		6,205
Earnings from consolidated entities	0		0
Adjustments to reconcile net earnings to cash provided by operations:
Depreciation	12,978		11,269
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	(792)		(1,804)
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	(706)		(229)
Capitalization of deferred policy acquisition costs	0		0
Other assets	(2,715)		(569)
Related party assets	(3)		2
Accounts payable and accrued expenses	290		538
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	4,270		0
Net cash provided by operating activities	16,808		15,412
Purchases of:
Property, plant and equipment	(253,622)		(70,924)
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0		0
Preferred stock	0		0
Real estate	0		(243)
Mortgage loans	(20,196)		(30,590)
Proceeds from sale and paydowns of:
Property, plant and equipment	1,477		5,236
Short term investments	0		0
Fixed maturities investments	0		0
Equity securities	0		0
Preferred stock	0		0
Real estate	0		667
Mortgage loans	38,398		29,500
Net cash used by investing activities	(233,943)		(66,354)
Cash flow from financing activities:
Borrowings from credit facilities	206,087		161,700
Principal repayments on credit facilities	(88,605)		(91,948)
Debt issuance costs	(2,712)		(2,051)
Capital lease payments	0		0
Leveraged Employee Stock Ownership Plan - repayments from loan	0		0
Securitization deposits	0		0
Common stock dividends paid			0
Net contribution from (to) related party			0
Proceeds from (repayment of) intercompany loans	103,024		(16,030)
Investment contract deposits	0		0
Investment contract withdrawals	0		0
Net cash provided by financing activities	217,794		51,671
Effects of exchange rate on cash	0		0
Increase in cash and cash equivalents	659		729
Cash and cash equivalents at the beginning of period	1,515		775
Cash and cash equivalents at the end of the period	2,174		1,504
Operating Segments | Moving and Storage Operating Segment | Moving and Storage Operating Eliminations
Cash flow from operating activities:
Net earnings	(239,660)		(175,647)
Earnings from consolidated entities	239,660		175,647
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	[7]	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		0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	(2,514)	[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		0
Capital lease payments	0		0
Leveraged Employee Stock Ownership Plan - repayments from loan	0		0
Securitization deposits	0		0
Common stock dividends paid			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 provided 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	(23,864)		(12,912)
Earnings from consolidated entities	23,864		12,912
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	159	[7]	791	[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	(159)	[7]	(791)	[7]
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	11,589	[7]	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		0
Preferred stock	0		0
Real estate	0		0
Mortgage loans	(11,589)	[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		0
Capital lease payments	0		0
Leveraged Employee Stock Ownership Plan - repayments from loan	0		0
Securitization deposits	0		0
Common stock dividends paid			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 provided 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] Balance for the nine months ended September 30, 2013

[2] Balance for the nine months ended September 30, 2012

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

[4] Balances for the nine months ended September 30, 2012

[5] Balances as of December 31, 2012

[6] Balances as of September 30, 2013

[7] Elimination of intercompany investments