Name:	uhal_ApplicableMarginPerLoanAgreementMaximumRate
Namespace Prefix:	uhal_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Fleet loan provision specified LIBOR plus applicable margin. This is the lower of the two applicable margin rates at the time of the loan agreement.

No definition available.

Name:	uhal_ApplicableMarginPerLoanAgreementMinimumRate
Namespace Prefix:	uhal_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Historic applicable margins. This is the higher of the rate range.

No definition available.

Name:	uhal_ApplicableMarginsHighRate
Namespace Prefix:	uhal_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Historic applicable margin. This is the lower of the rate range.

No definition available.

Name:	uhal_ApplicableMarginsLowRate
Namespace Prefix:	uhal_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The stated principal amount of the debt instrument includes a new note added during the life of the debt, which may vary from the carrying amount because of unamortized premium or discount.

No definition available.

Name:	uhal_DebtInstrumentAssociateAnotherNoteAmount
Namespace Prefix:	uhal_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Earliest date the capital lease obligation was issued.

No definition available.

Name:	uhal_DebtInstrumentEarliestIssuanceDate
Namespace Prefix:	uhal_
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

The stated principal amount of the debt instrument increased some time during the life of the debt, which may vary from the carrying amount because of unamortized premium or discount.

No definition available.

Name:	uhal_DebtInstrumentIncreaseInFaceAmount
Namespace Prefix:	uhal_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The terms of the debt agreement were changed after the effective date of the loan. The marginal interest rate was also changed at this time. This is the new interest rate under the new terms of the agreement.

No definition available.

Name:	uhal_DebtInstrumentInterestRateEffectivePercentageAdjusted
Namespace Prefix:	uhal_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Name:	uhal_DebtInstrumentIssuanceAndMaturityDatesAbstract
Namespace Prefix:	uhal_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Latest date the capital lease obligation was issued.

No definition available.

Name:	uhal_DebtInstrumentLatestIssuanceDate
Namespace Prefix:	uhal_
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

Name:	uhal_DebtInstrumentMiscellaneousInformationAbstract
Namespace Prefix:	uhal_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The debt agreement amount at the beginning of this contract. It is no longer valid because of a subsequent amendment in the terms of this loan.

No definition available.

Name:	uhal_DebtInstrumentOriginalFaceAmount
Namespace Prefix:	uhal_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Name:	uhal_DebtInstrumentsFacePaymentAndRemainingBalanceAmountAbstract
Namespace Prefix:	uhal_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

We include two different LIBOR rates for these loans in our documentation.

No definition available.

Name:	uhal_HighLiborRate
Namespace Prefix:	uhal_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Loan date modification and extension of a revolving credit loan.

No definition available.

Name:	uhal_LoanModificationAndExtensionDate
Namespace Prefix:	uhal_
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

Purchase of equipment throughout a fiscal year.

No definition available.

Name:	uhal_PurchaseEquipmentThroughFiscalYear
Namespace Prefix:	uhal_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

The amount of corporate (parent company) debt held by our insurance subsidiaries.

No definition available.

Name:	uhal_SubsidiariesShareOfDebtPurchasedFromParent
Namespace Prefix:	uhal_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Terms of the loan were amended on this date.

No definition available.

Name:	uhal_TermNoteAmendedDate
Namespace Prefix:	uhal_
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.13,16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Name:	us-gaap_DebtAndCapitalLeaseObligations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 16, 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The effective interest rate at the end of the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_DebtInstrumentInterestRateAtPeriodEnd
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentageAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Interest rate stated in the contractual debt agreement.

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentageAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

When presenting a range of interest rates, the highest stated (contractual) rate for funds borrowed under the debt agreement as of the balance sheet date.

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMaximum
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

When presenting a range of interest rates, the lowest stated (contractual) rate for funds borrowed under the debt agreement as of the balance sheet date.

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMinimum
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Date when the debt instrument was issued, which may be presented in a variety of ways (year, month and year, day, month and year, quarter, etc.).

Name:	us-gaap_DebtInstrumentIssuanceDate
Namespace Prefix:	us-gaap_
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

Date when the debt instrument is scheduled to be fully repaid, which may be presented in a variety of ways (year, month and year, day, month and year, quarter, etc.).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

When presenting a range of maturity dates, the latest date when the outstanding debt instruments are required to be repaid. May be presented in a variety of ways (for example: year only, month and year, day, month and year, and number of years).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_DebtInstrumentMaturityDateRangeEnd
Namespace Prefix:	us-gaap_
Data Type:	us-types:dateStringItemType
Balance Type:	na
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When presenting a range of maturity dates, the earliest date when the outstanding debt instruments are required to be repaid. May be presented in a variety of ways (for example: year only, month and year, day, month and year, and number of years).

Name:	us-gaap_DebtInstrumentMaturityDateRangeStart
Namespace Prefix:	us-gaap_
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

A general description of the lessee's leasing arrangements including, but not limited to, the following: a) the basis on which contingent rental payments are determined; (b) the existence and terms of renewal or purchase options and escalation clauses; (c) restrictions imposed by lease agreements, such as those concerning dividends, additional debt, and further leasing.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 440

-SubTopic 10

-Section 25

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6394851&loc=SL2265659-115463

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6452660&loc=d3e36991-112694

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 01-8

-Paragraph 7, 8, 10, 14

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 10

-Section 15

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=6451445&loc=d3e32400-112679

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 16

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 1

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_DescriptionOfLesseeLeasingArrangementsCapitalLeases
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time.

Name:	us-gaap_LongTermDebtPercentageBearingVariableInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The stated maturity date of the mortgage loan receivable on real estate or a range of maturity dates for a group of loans.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 310

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-29)

-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule IV

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 29

-Article 12

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 10

-Section S99

-Paragraph 6

-Subparagraph (SX 210.5-04.(c) Schedule IV)

-URI http://asc.fasb.org/extlink&oid=6882300&loc=d3e5864-122674