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Represents a percentage of the available-for-sale securities portfolio.

+ References

No definition available.

+ Details

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- Definition

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

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- Definition

The fair value of available-for-sale securities that serve as collateral for borrowings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5086-111524

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- Definition

The cumulative amount of credit losses recognized in earnings related to debt securities held for which a portion of an other than temporary impairment (OTTI) was recognized in other comprehensive income (a component of shareholders' equity).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27340-111563

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Note 6 - Investment Securities Available For Sale (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Note 6 - Investment Securities Available For Sale (Details) [Line Items]
Available-for-sale Securities Pledged as Collateral (in Dollars)	$ 61,500,000	$ 61,900,000
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	54
Available-for-sale Securities, Percentage of Portfolio	98.00%mbcn_PercentageOfPortfolio
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held (in Dollars)	$ 0
Available-for-sale Securities [Member]
Note 6 - Investment Securities Available For Sale (Details) [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	0		0