Fair value of common stock issued by the Company included in plan assets.

No definition available.

Name:	mufg_DefinedBenefitPlanFairValueOfCommonStockIssuedIncludedInPlanAssets
Namespace Prefix:	mufg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents the fair value of debt securities issued by the Company included in plan assets.

+ References

No definition available.

+ Details

Name:	mufg_DefinedBenefitPlanFairValueOfDebtSecuritiesIssuedIncludedInPlanAssets
Namespace Prefix:	mufg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of fair value of common stock issued by the Company included in plan assets to the total fair value of plan assets.

+ References

No definition available.

+ Details

Name:	mufg_DefinedBenefitPlanPercentageOfFairValueOfCommonStockIssuedToTotalFairValueOfPlanAssets
Namespace Prefix:	mufg_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the percentage fair value of debt securities issued by the Company to the total fair value of plan assets.

+ References

No definition available.

+ Details

Name:	mufg_DefinedBenefitPlanPercentageOfFairValueOfDebtSecuritiesIssuedToTotalFairValueOfPlanAssets
Namespace Prefix:	mufg_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the eligible age of employee from when lifetime annuity payments commence.

+ References

No definition available.

+ Details

Name:	mufg_EligibleAgeForLifetimeAnnuityPayments
Namespace Prefix:	mufg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Major Fund Types

+ References

No definition available.

+ Details

Name:	mufg_NumberOfMajorFundTypes
Namespace Prefix:	mufg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of cost of providing special or contractual termination benefits payable from defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (q)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_DefinedBenefitPlanCostOfProvidingSpecialOrContractualTerminationBenefitRecognizedDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RetirementPlanTypeAxis=mufg_PensionBenefitsAndSIPsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanSponsorLocationAxis=country_JP
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=mufg_OtherDebtSecuritiesAndJapaneseDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=mufg_JapaneseMarketableEquitySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Severance Indemnities and Pension Plans (Narrative) (Detail) ¥ in Millions	12 Months Ended
	Mar. 31, 2025 JPY (¥) fund	Mar. 31, 2024 JPY (¥)	Mar. 31, 2023 JPY (¥)	Mar. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Eligible age for lifetime annuity payments				65 months
Special lump-sum early termination benefits charged to operations for the fiscal year	¥ 14,089	¥ 19,116	¥ 16,888
Pension benefits and SIPs
Defined Benefit Plan Disclosure [Line Items]
Number of major fund types \| fund	4
Domestic, Japan \| Pension benefits and SIPs \| Other debt securities and Japanese debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of debt securities issued by the MUFG Group included in plan assets	¥ 2,615	¥ 2,355
Percentage of fair value of debt securities issued by the MUFG Group to total fair value of plan assets	0.07%	0.07%
Domestic, Japan \| Pension benefits and SIPs \| Japanese marketable equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of common stock issued by the MUFG Group included in plan assets	¥ 7,076	¥ 8,022
Percentage of fair value of common stock issued by the MUFG Group to total fair value of plan assets	0.20%	0.23%