Certain loans acquired in transfer not accounted for as debt securities carrying amount gross.

No definition available.

Name:	mfsf_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesCarryingAmountGross
Namespace Prefix:	mfsf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value at acquisition of acquired loans accounted for as debt securities with evidence of deterioration of credit quality.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

+ Details

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

- Definition

The aggregate excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan. This relates to loans with deteriorating of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

No definition available.

+ Details

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

- Definition

The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

+ Details

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

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

+ Details

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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=mfsf_UniversalBancorpMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_RealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=mfsf_OtherLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_FirstMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_SecondMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_AutomobileLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mfsf_ConsumerRecreationalVehicleFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mfsf_OtherClassOfFinancingReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialAndIndustrialSectorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Accounting for Certain Loans Acquired in a Transfer (Schedule of Acquired Loans) (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Feb. 28, 2018	Dec. 31, 2017
Total loans receivable	$ 1,488,948,000	$ 1,497,256,000		$ 1,186,713,000
Acquired loans with evidence of deterioration, fair value			$ 313,000
Accretable yield	1,700,000	2,800,000
Universal Bancorp [Member]
Total loans receivable	130,755,000	179,968,000
Carrying amount, gross	129,045,000	177,169,000
Allowance	(129,045,000)	(177,169,000)
Carrying amount net of allowance	129,045,000	177,169,000
Commercial Real Estate [Member]
Total loans receivable	504,241,000	485,808,000
Real estate [Member]
Total loans receivable	1,045,198,000	1,080,729,000
Real estate [Member] \| Universal Bancorp [Member]
Total loans receivable	121,626,000	167,639,000
Real estate [Member] \| Commercial Real Estate [Member]
Total loans receivable	504,241,000	485,808,000
Real estate [Member] \| Commercial Real Estate [Member] \| Universal Bancorp [Member]
Total loans receivable	84,848,000	120,249,000
Other [Member]
Total loans receivable	443,750,000	416,527,000
Other [Member] \| Universal Bancorp [Member]
Total loans receivable	9,129,000	12,329,000
Construction Loans [Member] \| Commercial Segment [Member]
Total loans receivable	49,496,000	53,310,000
Construction Loans [Member] \| Real estate [Member] \| Commercial Segment [Member]
Total loans receivable	49,496,000	53,310,000
Construction Loans [Member] \| Real estate [Member] \| Commercial Segment [Member] \| Universal Bancorp [Member]
Total loans receivable	6,108,000	8,664,000
First Mortgage [Member] \| Consumer [Member]
Total loans receivable	415,865,000	464,539,000
First Mortgage [Member] \| Real estate [Member] \| Consumer [Member]
Total loans receivable	415,865,000	464,539,000
First Mortgage [Member] \| Real estate [Member] \| Consumer [Member] \| Universal Bancorp [Member]
Total loans receivable	24,218,000	30,694,000
Second Mortgage [Member] \| Consumer [Member]
Total loans receivable	75,596,000	77,072,000
Second Mortgage [Member] \| Real estate [Member] \| Consumer [Member]
Total loans receivable	75,596,000	77,072,000
Second Mortgage [Member] \| Real estate [Member] \| Consumer [Member] \| Universal Bancorp [Member]
Total loans receivable	6,452,000	8,032,000
Automobile Loan [Member] \| Consumer [Member]
Total loans receivable	57,107,000	43,667,000
Automobile Loan [Member] \| Other [Member] \| Consumer [Member]
Total loans receivable	57,107,000	43,667,000
Automobile Loan [Member] \| Other [Member] \| Consumer [Member] \| Universal Bancorp [Member]
Total loans receivable	524,000	1,138,000
Boat/RVs [Member] \| Consumer [Member]
Total loans receivable	213,305,000	216,608,000
Boat/RVs [Member] \| Other [Member] \| Consumer [Member]
Total loans receivable	213,305,000	216,608,000
Boat/RVs [Member] \| Other [Member] \| Consumer [Member] \| Universal Bancorp [Member]
Total loans receivable	17,000	97,000
Other [Member] \| Consumer [Member]
Total loans receivable	7,319,000	6,893,000
Other [Member] \| Other [Member] \| Consumer [Member]
Total loans receivable	7,319,000	6,893,000
Other [Member] \| Other [Member] \| Consumer [Member] \| Universal Bancorp [Member]
Total loans receivable	311,000	523,000
Commercial and Industrial [Member] \| Commercial Segment [Member]
Total loans receivable	166,019,000	149,359,000
Commercial and Industrial [Member] \| Other [Member] \| Commercial Segment [Member]
Total loans receivable	166,019,000	149,359,000
Commercial and Industrial [Member] \| Other [Member] \| Commercial Segment [Member] \| Universal Bancorp [Member]
Total loans receivable	$ 8,277,000	$ 10,571,000