Name:	msfg_FinancingReceivableModificationsAdditionalDisclosuresAbstract
Namespace Prefix:	msfg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The number of financing receivables that have been modified during the period by troubled debt restructurings.

No definition available.

Name:	msfg_FinancingReceivableModificationsNumberOfLoans
Namespace Prefix:	msfg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The amount of outstanding recorded investment related to financing receivables that have been modified by other than troubled debt restructurings.

No definition available.

Name:	msfg_FinancingReceivableModificationsOtherThanTroubledDebtRestructuringsRecordedInvestment
Namespace Prefix:	msfg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the amount of additional commitments to lend to customers whose investments in financing receivables are modified by troubled debt restructurings.

No definition available.

Name:	msfg_FinancingReceivableModificationsPostModificationAdditionalRecordedInvestment
Namespace Prefix:	msfg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the amount of specific reserves allocated to customers whose investments in financing receivables are modified by troubled debt restructurings.

No definition available.

Name:	msfg_FinancingReceivableModificationsPostModificationAllocatedSpecificReserves
Namespace Prefix:	msfg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Reflects the amount of the write-down related to financing receivables that have been modified by troubled debt restructurings for which there was a payment default within twelve months following the modification during the period.

No definition available.

Name:	msfg_FinancingReceivableModificationsSubsequentPaymentDefaultImpairedTroubledDebtRestructuringWriteDown
Namespace Prefix:	msfg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Number of financing receivables that have been modified by troubled debt restructurings for which there was a payment default within twelve months following the modification during the period.

No definition available.

Name:	msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans
Namespace Prefix:	msfg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Amount of outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings for which there was a payment default within twelve months following the modification during the period.

No definition available.

Name:	msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment
Namespace Prefix:	msfg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the increase in allowance for loan losses due to troubled debt restructurings for financing receivables that have been modified by troubled debt restructurings for which there was a payment default within twelve months following the modification during the period.

No definition available.

Name:	msfg_FinancingReceivableModificationsSubsequentPaymentDefaultTroubledDebtRestructuringIncreaseInAllowanceForLoanLosses
Namespace Prefix:	msfg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

Name:	msfg_FinancingReceivableModificationsWithinPreviousTwelveMonthsSubsequentlyDefaultedDuringCurrentPeriodAbstract
Namespace Prefix:	msfg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The amount of the outstanding recorded investment related to financing receivables that have been modified during the period by troubled debt restructurings after the financing receivable has been modified.

No definition available.

Name:	msfg_FinancingReceivablePostModificationRecordedInvestment
Namespace Prefix:	msfg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The amount of the outstanding recorded investment related to financing receivables that have been modified during the period by troubled debt restructurings before the financing receivable has been modified.

No definition available.

Name:	msfg_FinancingReceivablePreModificationRecordedInvestment
Namespace Prefix:	msfg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the period of contractually past due loans, to be considered as payment default under the modified terms.

No definition available.

Name:	msfg_FinancingReceivablesPeriodOfModifiedContractuallyPastDueLoansToBeConsideredAsPaymentDefault
Namespace Prefix:	msfg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Number of financing receivables that have been modified by troubled debt restructurings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 33

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953676-111524

Name:	us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 40

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18845-111554

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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Namespace Prefix:
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Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix:
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=msfg_CommercialAndIndustrialLoanMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=msfg_OtherReceivableMember
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Data Type:	na
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Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=msfg_HotelReceivableMember
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Data Type:	na
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialPortfolioSegmentMember
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Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=msfg_Family1To4Member
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