XML 97 R65.htm IDEA: XBRL DOCUMENT v3.5.0.2

Loans and Related Allowance for Loan and Lease Losses - Troubled Debt Restructurings Subsequently Defaulted (Detail)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Commercial And Industrial [Member]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	1	1	2	3	2		5
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 3,000	$ 8,000	$ 273,000	$ 55,000	$ 14,000		$ 574,000
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	1					1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 58,000					$ 15,000
Real Estate Mortgage Portfolio Segment [Member] | Commercial Loans [Member]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts							1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment							$ 190,000
Real Estate Construction Porfolio Segment [Member]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts			1	1	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment			$ 58,000	$ 152,000	$ 130,000
Consumer Portfolio Segment [Member]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts		1		1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 8,000		$ 8,000

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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=66008989&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 of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953682-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

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