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Number of a cumulative period in month commencing from the contractual due date of loans for categorizing internal borrower ratings, for which generally have the overdue principal or interest payments, in 'PnD' format.

No definition available.

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Number of period of loans contractually past due by segment before becoming defaulted loans in 'PnYnMnDTnHnMnS' format.

No definition available.

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Number of months of loans contractually past due before being placed on nonaccrual status, in 'PnM' format.

No definition available.

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Number of days of temporary extensions of maturity dates to nonaccrual loans in 'PnD' format.

No definition available.

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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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph c
-Publisher SEC

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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Amount of decrease in financing receivable from sale. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-11

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

Amount of decrease in financing receivable from sale and reclassification to held-for-sale. Excludes net investment in lease.

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11B
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-11B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-11

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

Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

No definition available.

Name:	us-gaap_OtherCommitment
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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Balance Type:
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Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=mufg_NonperformingLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_InternalCreditAssessmentAxis=mufg_CloseWatchMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Namespace Prefix:
Data Type:	na
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Namespace Prefix:
Data Type:	na
Balance Type:
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Data Type:	na
Balance Type:
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Namespace Prefix:
Data Type:	na
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Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=mufg_MUFGAmericasHoldingsPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
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