Evaluation and assessment of customer credit worthiness over a specified time.

No definition available.

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

- Definition

Percentage of estimated gain loss.

+ References

No definition available.

+ Details

Name:	uhal_PercentageOfEstimatedGainLoss
Namespace Prefix:	uhal_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Ratio of insurance contracts that are subject to reinsurance participation to all contracts in force.

+ References

No definition available.

+ Details

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

The gain (loss) resulting from the sale of credit card receivables (portfolios).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-3

+ Details

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

- Definition

Carrying amount as of the balance sheet date of noncurrent interest earned but not received. Also called accrued interest or accrued interest receivable.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(17))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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

- Definition

Gross amount, as of the balance sheet date, due the entity from (a) agents and insureds, (b) uncollected premiums and (c) others, before deducting the allowance for doubtful accounts.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(5))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

+ Details

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

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CreditCardReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_UnfundedLoanCommitmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Allowance for Credit Losses (Narratives) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Mar. 31, 2025
Financing Receivable Impaired [Line Items]
Percentage of estimated gain loss	4.00%
Paid and unpaid percentage		1.00%
Allowance for expected credit losses	$ 5.5		$ 5.1
Available for sale securities, accrued interest receivable	28.9		29.4
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable Impaired [Line Items]
Premiums Receivable Gross	$ 1.0		$ 0.1
Credit card receivables
Financing Receivable Impaired [Line Items]
Average Historical Chargeback Term	The Company rents equipment to corporate customers for which payment terms are 30 days.
Accrued interest receivables
Financing Receivable Impaired [Line Items]
Average Historical Chargeback Term	Historical credit loss experience provides additional support for the estimation of expected credit losses. In assessing the credit losses, the portfolio is reviewed on a collective basis, using loan-specific cash flows to determine the fair value of the collateral in the event of default. Adjustments to this analysis are made to assess loans with a loan-to-value of 65% or greater.