Name:	uhal_CashGeneratedFromAgreementsAndNotes
Namespace Prefix:	uhal_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

These agreements and notes with subsidiaries of SAC Holdings, 4 SAC, 5 SAC, Galaxy and Private Mini, Excluded Dealer Agreements commission expenses.

No definition available.

Name:	uhal_CommissionExpensesGeneratedFromDealerAgreementWithRelatedParty
Namespace Prefix:	uhal_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of revenue received excluding any revenue generated from dealer commissions or expenses as part of the dealer contract between the Company and these related party entities.

No definition available.

Name:	uhal_RevenueExcludingDealerAgreementCommissionsAndExpenses
Namespace Prefix:	uhal_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

This provides just the cost and expense for SAC holdings.

No definition available.

Name:	uhal_SacHoldingsLeaseAndRentalExpense
Namespace Prefix:	uhal_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of cash paid to purchase other assets as part of operating activities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3536-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3367-108585

Name:	us-gaap_PaymentsForPurchaseOfOtherAssets1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

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

The percentage charged for managing real estate properties.

No definition available.

Name:	us-gaap_PropertyManagementFeePercentFee
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

The amount of revenue derived from managing real estate properties.

No definition available.

Name:	us-gaap_PropertyManagementFeeRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

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

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=uhal_SacHoldingsMercuryFourSacFiveSacGalaxyAndPrivateMiniMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: