LOANS AND ALLOWANCE FOR LOAN LOSSES (Schedule of Reported Investment in Loans, Net of Deferred Fees and Costs, by Portfolio Segment and Based on Impairment Method) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Loans and allowance for loan losses ("ALLL") [Line Items]
Beginning balance	$ 3,439	$ 3,449	$ 3,440	$ 3,493
Charge-offs	(7)	(44)	(22)	(102)
Recoveries	$ 5	6	$ 19	20
Provision (decrease) increase		50		50
Ending balance	$ 3,437	3,461	$ 3,437	3,461
Commercial [Member]
Loans and allowance for loan losses ("ALLL") [Line Items]
Beginning balance	276	$ 109	353	$ 184
Charge-offs	$ (2)		$ (2)
Recoveries
Provision (decrease) increase	$ 54	$ 19	$ (23)	$ (56)
Ending balance	328	128	328	128
Commercial Real Estate [Member]
Loans and allowance for loan losses ("ALLL") [Line Items]
Beginning balance	$ 944	$ 780	$ 579	$ 808
Charge-offs
Recoveries
Provision (decrease) increase	$ (19)	$ 7	$ 346	$ (21)
Ending balance	925	787	925	787
Faith Based Non-Profit [Member]
Loans and allowance for loan losses ("ALLL") [Line Items]
Beginning balance	$ 1,450	$ 1,686	$ 1,234	$ 1,883
Charge-offs
Recoveries
Provision (decrease) increase	$ (76)	$ 74	$ 140	$ (123)
Ending balance	1,374	1,760	1,374	1,760
Residential Real Estate [Member]
Loans and allowance for loan losses ("ALLL") [Line Items]
Beginning balance	$ 394	645	685	493
Charge-offs		(40)	(7)	(71)
Recoveries	$ 3	4	15	13
Provision (decrease) increase	(7)	(7)	(303)	167
Ending balance	390	602	390	602
Consumer [Member]
Loans and allowance for loan losses ("ALLL") [Line Items]
Beginning balance	$ 23	$ 27	28	19
Charge-offs			(1)	(16)
Recoveries			1	1
Provision (decrease) increase			(5)	23
Ending balance	$ 23	$ 27	23	27
Other [Member]
Loans and allowance for loan losses ("ALLL") [Line Items]
Beginning balance	204	109	265	106
Charge-offs	(5)	(4)	(12)	(15)
Recoveries	2	2	3	6
Provision (decrease) increase	44	50	(11)	60
Ending balance	245	157	245	$ 157
Unallocated [Member]
Loans and allowance for loan losses ("ALLL") [Line Items]
Beginning balance	$ 148	$ 93	$ 296
Charge-offs
Recoveries
Provision (decrease) increase	$ 4	$ (93)	$ (144)
Ending balance	$ 152		$ 152

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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

- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

+ Details

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

+ Details

Name:	us-gaap_LoansAndLeasesReceivableAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of expense related to estimated loss from loan and lease transactions.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.11)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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