Name:	uhal_LargestAggregateBalanceInReportingPeriod
Namespace Prefix:	uhal_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The US-GAAP taxonomy only contains a single rate for related party transactions: RelatedPartyTransactionRate. We disclose a range of rates for management fees.

No definition available.

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

One time interest payment received on loans and other debt instruments.

No definition available.

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

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

The US-GAAP taxonomy only contains a single date for related party transactions. RelatedPartyTransaction Date. We disclose our earliest and latest maturities on the various outstanding notes only by the year.

No definition available.

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

The US-GAAP taxonomy only contains a single rate for related party transactions: RelatedPartyTransactionRate. We disclose a range of rates for management fees.

No definition available.

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

Reflects the amount of collections received from related parties to reduce the carrying amounts of loans and leases receivable due from them.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

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 210.9-03.7(e))

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph e

-Article 9

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

Base revenue, as contractually stipulated, for operating and managing another entity's business during the reporting period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1(d))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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

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

For an unclassified balance sheet, amounts due from parties associated with the reporting entity as evidenced by a written promise to pay.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(k)(1))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph k

-Subparagraph 1

-Article 4

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 3

-Article 7

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.3)

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Related Parties

-URI http://asc.fasb.org/extlink&oid=16382449

Name:	us-gaap_NotesReceivableRelatedParties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Interest received on loans and other debt instruments during the current period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585

Name:	us-gaap_ProceedsFromInterestReceived
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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

Name:	us-gaap_StatementBusinessSegmentsAxis=uhal_AmercoBusinessSegmentMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_StatementBusinessSegmentsAxis=uhal_AmercoUhaulIntlMember
Namespace Prefix:
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