XML 80 R61.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Note 5 - Loans and Related Allowance for Loan and Lease Losses (Details Textual) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2018 USD ($) | Sep. 30, 2018 USD ($) | Jun. 30, 2018 USD ($) | Mar. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Sep. 30, 2017 USD ($) | Jun. 30, 2017 USD ($) | Mar. 31, 2017 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($)
Loans and Leases Receivable, Deferred Income, Total | $ 1,600,000 |  |  |  | $ 1,500,000 |  |  |  | $ 1,600,000 | $ 1,500,000
Financing Receivable, Modifications, Recorded Investment | 4,400,000 |  |  |  | 5,400,000 |  |  |  | 4,400,000 | 5,400,000
Financing Receivable, Allowance for Credit Losses, Write-downs |  |  |  |  |  |  |  |  | $ 459,000 | $ 509,000
Financing Receivable, Modifications, Subsequent Default, Number of Contracts |  |  |  |  |  |  |  |  |  | 0
Number of Days Past Due |  |  |  |  |  |  |  |  | 90 days |
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans |  |  |  |  |  |  |  |  | $ 456,000 | $ 437,000
Allowance for Loan and Lease Losses, Write-offs |  |  |  |  |  |  |  |  | 1,118,000 | 1,154,000
Provision for Loan and Lease Losses, Total | 210,000 | $ 210,000 | $ 210,000 | $ 210,000 | $ 430,000 | $ 280,000 | $ 170,000 | $ 165,000 |  |
Real Estate Construction Porfolio Segment [Member] |  |  |  |  |  |  |  |  |  |
Loans and Leases Receivable, Historical Loss Rate |  |  |  | (0.127%) |  |  |  | 0.775% |  |
Allowance for Loan and Lease Losses, Write-offs |  |  |  |  |  |  |  |  | 0 |
Provision for Loan and Lease Losses, Total |  |  |  |  |  |  |  |  |  | $ 1,200,000
Threshold For Loans Evaluated For Impairment [Member] |  |  |  |  |  |  |  |  |  |
Loans and Leases Receivable, before Fees, Gross, Total | 500,000 |  |  |  |  |  |  |  | 500,000 |
Threshold For Loans Evaluated For Impairment [Member] | Outside Consultant [Member] |  |  |  |  |  |  |  |  |  |
Loans and Leases Receivable, before Fees, Gross, Total | 250,000 |  |  |  |  |  |  |  | 250,000 |
Threshold For Loans Evaluated For Impairment [Member] | Criticized Relationships [Member] |  |  |  |  |  |  |  |  |  |
Financing Receivable, Gross | $ 125,000 |  |  |  |  |  |  |  | $ 125,000 |

X
- Definition Represents the historical loss rate for loans and leases held in portfolio, including but not limited to, commercial and consumer loans. + References No definition available. + Details
Name: | mbcn_LoansAndLeasesReceivableHistoricalLossRate
Namespace Prefix: | mbcn_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of days past due. + References No definition available. + Details
Name: | mbcn_NumberOfDaysPastDue
Namespace Prefix: | mbcn_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -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 + Details
Name: | us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of direct write-downs of financing receivables charged against the allowance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554 + Details
Name: | us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, before allowance and fees, of loans and leases receivable. 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_LoansAndLeasesReceivableBeforeFeesGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for 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 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=84165051&loc=d3e45377-112738 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 20 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=84159169&loc=d3e10152-111534 + Details
Name: | us-gaap_LoansAndLeasesReceivableDeferredIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18794-111554 + Details
Name: | us-gaap_LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.10(3)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_NotesReceivableGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of expense related to estimated loss from loan and lease transactions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.11) -URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_ProvisionForLoanAndLeaseLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=mbcn_RealEstateConstructionPorfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mbcn_ThresholdForLoansEvaluatedForImpairmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis=mbcn_OutsideConsultantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis=mbcn_CriticizedRelationshipsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |