XML 20 R70.htm IDEA: XBRL DOCUMENT v2.4.1.9
LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 6) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
item
Dec. 31, 2013
item
Dec. 31, 2012
item
Troubled debt restructurings      
Total of troubled debt restructurings $ 23,325us-gaap_FinancingReceivableModificationsRecordedInvestment $ 14,347us-gaap_FinancingReceivableModificationsRecordedInvestment  
Allocated specific reserves 485msfg_FinancingReceivableModificationsPostModificationAllocatedSpecificReserves 534msfg_FinancingReceivableModificationsPostModificationAllocatedSpecificReserves  
Amounts Company has committed to lend to customers with outstanding loans classified as troubled debt restructurings 0msfg_FinancingReceivableModificationsPostModificationAdditionalRecordedInvestment 0msfg_FinancingReceivableModificationsPostModificationAdditionalRecordedInvestment  
Loans by class modified as troubled debt restructurings      
Number of Loans 11msfg_FinancingReceivableModificationsNumberOfLoans 13msfg_FinancingReceivableModificationsNumberOfLoans 14msfg_FinancingReceivableModificationsNumberOfLoans
Pre-Modification Outstanding Recorded Investment 17,065msfg_FinancingReceivablePreModificationRecordedInvestment 781msfg_FinancingReceivablePreModificationRecordedInvestment 14,312msfg_FinancingReceivablePreModificationRecordedInvestment
Post-Modification Outstanding Recorded Investment 13,253msfg_FinancingReceivablePostModificationRecordedInvestment 781msfg_FinancingReceivablePostModificationRecordedInvestment 11,679msfg_FinancingReceivablePostModificationRecordedInvestment
Increase in allowance for loan losses due to troubled debt restructurings 130msfg_FinancingReceivablesTroubledDebtRestructuringIncreaseInAllowanceForLoanLosses 30msfg_FinancingReceivablesTroubledDebtRestructuringIncreaseInAllowanceForLoanLosses 10msfg_FinancingReceivablesTroubledDebtRestructuringIncreaseInAllowanceForLoanLosses
Charge offs due to troubled debt restructurings 3,849us-gaap_FinancingReceivablesImpairedTroubledDebtRestructuringWriteDown 442us-gaap_FinancingReceivablesImpairedTroubledDebtRestructuringWriteDown 2,477us-gaap_FinancingReceivablesImpairedTroubledDebtRestructuringWriteDown
Loans by class modified as troubled debt restructurings for which there was a payment default within twelve months following the modification      
Number of Loans 4msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans 4msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans 16msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans
Recorded Investment 1,547msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment 108msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment 5,987msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment
Period of contractually past due loans under the modified terms, to be considered in payment default 90 days    
Allowance for loan losses increased due to troubled debt restructurings 0msfg_FinancingReceivableModificationsSubsequentPaymentDefaultTroubledDebtRestructuringIncreaseInAllowanceForLoanLosses 0msfg_FinancingReceivableModificationsSubsequentPaymentDefaultTroubledDebtRestructuringIncreaseInAllowanceForLoanLosses 256msfg_FinancingReceivableModificationsSubsequentPaymentDefaultTroubledDebtRestructuringIncreaseInAllowanceForLoanLosses
Charge offs due to troubled debt restructurings 0msfg_FinancingReceivableModificationsSubsequentPaymentDefaultImpairedTroubledDebtRestructuringWriteDown 0msfg_FinancingReceivableModificationsSubsequentPaymentDefaultImpairedTroubledDebtRestructuringWriteDown 1,192msfg_FinancingReceivableModificationsSubsequentPaymentDefaultImpairedTroubledDebtRestructuringWriteDown
Additional disclosures      
Recorded investment of loans modified other than troubled debt restructurings 4,424msfg_FinancingReceivableModificationsOtherThanTroubledDebtRestructuringsRecordedInvestment 0msfg_FinancingReceivableModificationsOtherThanTroubledDebtRestructuringsRecordedInvestment  
Non-accrual      
Troubled debt restructurings      
Total of troubled debt restructurings 575us-gaap_FinancingReceivableModificationsRecordedInvestment
/ us-gaap_InternalCreditAssessmentAxis
= msfg_NonAccrualMember
3,566us-gaap_FinancingReceivableModificationsRecordedInvestment
/ us-gaap_InternalCreditAssessmentAxis
= msfg_NonAccrualMember
 
Performing      
Troubled debt restructurings      
Total of troubled debt restructurings 7,499us-gaap_FinancingReceivableModificationsRecordedInvestment
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_PerformingFinancingReceivableMember
6,593us-gaap_FinancingReceivableModificationsRecordedInvestment
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_PerformingFinancingReceivableMember
 
Commercial | Commercial and industrial      
Loans by class modified as troubled debt restructurings      
Number of Loans   1msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_CommercialAndIndustrialLoanMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember
2msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_CommercialAndIndustrialLoanMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember
Pre-Modification Outstanding Recorded Investment   28msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_CommercialAndIndustrialLoanMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember
179msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_CommercialAndIndustrialLoanMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember
Post-Modification Outstanding Recorded Investment   28msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_CommercialAndIndustrialLoanMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember
179msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_CommercialAndIndustrialLoanMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember
Loans by class modified as troubled debt restructurings for which there was a payment default within twelve months following the modification      
Number of Loans     3msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_CommercialAndIndustrialLoanMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember
Recorded Investment     2,195msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_CommercialAndIndustrialLoanMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember
Commercial Real Estate | Hotel      
Loans by class modified as troubled debt restructurings      
Number of Loans 2msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_HotelReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
  2msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_HotelReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Pre-Modification Outstanding Recorded Investment 15,362msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_HotelReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
  7,727msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_HotelReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Post-Modification Outstanding Recorded Investment 11,550msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_HotelReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
  5,968msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_HotelReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate | Other      
Loans by class modified as troubled debt restructurings      
Number of Loans 2msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_OtherReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
3msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_OtherReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
7msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_OtherReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Pre-Modification Outstanding Recorded Investment 1,015msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_OtherReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
344msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_OtherReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
6,241msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_OtherReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Post-Modification Outstanding Recorded Investment 1,015msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_OtherReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
344msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_OtherReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
5,367msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_OtherReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Loans by class modified as troubled debt restructurings for which there was a payment default within twelve months following the modification      
Number of Loans 1msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_OtherReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
  9msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_OtherReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Recorded Investment 1,431msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_OtherReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
  3,332msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_OtherReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial Real Estate | Development      
Loans by class modified as troubled debt restructurings for which there was a payment default within twelve months following the modification      
Number of Loans     1msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_DevelopmentReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Recorded Investment     323msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_DevelopmentReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Residential | 1-4 family residential mortgage loans      
Loans by class modified as troubled debt restructurings      
Number of Loans 5msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
7msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
1msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Pre-Modification Outstanding Recorded Investment 628msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
359msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
91msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Post-Modification Outstanding Recorded Investment 628msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
359msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
91msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Loans by class modified as troubled debt restructurings for which there was a payment default within twelve months following the modification      
Number of Loans 2msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
2msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
2msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Recorded Investment 102msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
89msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
125msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_Family1To4Member
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Residential | Home equity      
Loans by class modified as troubled debt restructurings      
Number of Loans 1msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
1msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
1msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Pre-Modification Outstanding Recorded Investment 34msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
20msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
70msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Post-Modification Outstanding Recorded Investment 34msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
20msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
70msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Loans by class modified as troubled debt restructurings for which there was a payment default within twelve months following the modification      
Number of Loans 1msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
1msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
1msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Recorded Investment 14msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
15msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
12msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_HomeEquityMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Consumer | Direct      
Loans by class modified as troubled debt restructurings      
Number of Loans 1msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_DirectMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
1msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_DirectMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
1msfg_FinancingReceivableModificationsNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_DirectMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
Pre-Modification Outstanding Recorded Investment 26msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_DirectMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
30msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_DirectMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
4msfg_FinancingReceivablePreModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_DirectMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
Post-Modification Outstanding Recorded Investment 26msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_DirectMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
30msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_DirectMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
4msfg_FinancingReceivablePostModificationRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_DirectMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
Loans by class modified as troubled debt restructurings for which there was a payment default within twelve months following the modification      
Number of Loans   1msfg_FinancingReceivableModificationsSubsequentPaymentDefaultNumberOfLoans
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_DirectMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
 
Recorded Investment   $ 4msfg_FinancingReceivableModificationsSubsequentPaymentDefaultRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= msfg_DirectMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
 
Minimum      
Troubled debt restructurings      
Period of modifications involving a reduction of the stated interest rate of the loan 60 months    
Period of modifications involving an extension of the maturity date 6 months    
Maximum      
Troubled debt restructurings      
Period of modifications involving a reduction of the stated interest rate of the loan 30 years    
Period of modifications involving an extension of the maturity date 480 months