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- References

No definition available.

Name:	mbin_ImpairedFinancingReceivableWithoutSpecificAllowanceAbstract
Namespace Prefix:	mbin_
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Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953550-111524

Name:	us-gaap_ImpairedFinancingReceivableRecordedInvestment
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Data Type:	xbrli:monetaryItemType
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Amount of allowance for credit losses related to recorded investment.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524

Name:	us-gaap_ImpairedFinancingReceivableRelatedAllowance
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Balance Type:	credit
Period Type:	instant

Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (a)(4)
-URI http://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524

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Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Amount of unpaid principal balance of impaired financing receivables for which there is no related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (a)(4)
-URI http://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

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Namespace Prefix:	us-gaap_
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Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (a)(4)
-URI http://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524

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Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=mbin_AgriculturalProductionAndRealEstatePortfolioSegmentMember
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