Name:	miff_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustment
Namespace Prefix:	miff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to lease acquired in connection with a business combination for which the initial accounting was incomplete.

No definition available.

Name:	miff_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentLease
Namespace Prefix:	miff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to mortgage servicing rights acquired in connection with a business combination for which the initial accounting was incomplete.

No definition available.

Name:	miff_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentMortgageServicingRights
Namespace Prefix:	miff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to time deposits acquired in connection with a business combination for which the initial accounting was incomplete.

No definition available.

Name:	miff_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentTimeDeposits
Namespace Prefix:	miff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to financial assets acquired in connection with a business combination for which the initial accounting was incomplete.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-4A

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-4

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

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to financial liabilities assumed in connection with a business combination for which the initial accounting was incomplete.

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

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to intangibles acquired in connection with a business combination for which the initial accounting was incomplete.

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

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to property, plant, and equipment acquired in connection with a business combination for which the initial accounting was incomplete.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 29
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-29

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-4A

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-4