Name:	mufg_ForeignExchangeDerivativeContracts
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Aggregate net gains and losses on all derivative instruments held for trading purposes whether or not settled physically, excluding foreign exchange derivative contracts.

No definition available.

Name:	mufg_InterestRateAndOtherDerivativeInstrumentsHeldForTradingPurposesNetGainsLosses
Namespace Prefix:	mufg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Trading Account Profits And Losses [Abstract]

No definition available.

Name:	mufg_TradingAccountProfitsAndLossesAbstract
Namespace Prefix:	mufg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of net gains and losses on trading account. Includes trading account profits and losses of trading account securities and trading derivative assets and liabilities, which exclude foreign exchange derivative contracts that are included in "Foreign exchange gains (losses)-net".

No definition available.

Name:	mufg_TradingAccountProfitsLossesExcludingForeignExchangeDerivativeContracts
Namespace Prefix:	mufg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Aggregate net gains and losses on trading securities, which include foreign currency-denominated debt securities such as foreign government or official institution bonds, corporate bonds, and mortgage-backed securities, excluding derivatives.

No definition available.

Name:	mufg_TradingAccountSecuritiesExcludingDerivativesNetGainsLosses
Namespace Prefix:	mufg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount of gain (loss) resulting from the difference between the acquisition price and the selling price or fair value of trading assets and trading liabilities, conducted separately from customer trading activities. Includes, but is not limited to, changes in fair value of trading assets and trading liabilities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4F
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-4F

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 940
-SubTopic 320
-Section 45
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481961/940-320-45-5

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 940
-SubTopic 320
-Section 35
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481992/940-320-35-3

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.13(e))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1