XML 37 R35.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Note 6 - Investment Securities Available For Sale (Details) - Amortized Cost and Fair Values of Securities Available for Sale (USD $) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2014 | Dec. 31, 2013
Note 6 - Investment Securities Available For Sale (Details) - Amortized Cost and Fair Values of Securities Available for Sale [Line Items] |  |
Amortized Cost | $ 156,527,000 | $ 160,532,000
Gross Unrealized Gains | 3,631,000 | 2,605,000
Gross Unrealized Losses | (4,218,000) | (5,994,000)
Fair Value | 155,940,000 | 157,143,000
Taxable [Member] | US States and Political Subdivisions Debt Securities [Member] |  |
Note 6 - Investment Securities Available For Sale (Details) - Amortized Cost and Fair Values of Securities Available for Sale [Line Items] |  |
Amortized Cost | 2,958,000 | 3,787,000
Gross Unrealized Gains | 107,000 | 46,000
Gross Unrealized Losses | (4,000) | (38,000)
Fair Value | 3,061,000 | 3,795,000
Tax-exempt [Member] | US States and Political Subdivisions Debt Securities [Member] |  |
Note 6 - Investment Securities Available For Sale (Details) - Amortized Cost and Fair Values of Securities Available for Sale [Line Items] |  |
Amortized Cost | 85,147,000 | 86,524,000
Gross Unrealized Gains | 2,384,000 | 1,562,000
Gross Unrealized Losses | (2,233,000) | (3,267,000)
Fair Value | 85,298,000 | 84,819,000
US Government Agencies Debt Securities [Member] |  |
Note 6 - Investment Securities Available For Sale (Details) - Amortized Cost and Fair Values of Securities Available for Sale [Line Items] |  |
Amortized Cost | 26,938,000 | 27,289,000
Gross Unrealized Gains | 209,000 | 135,000
Gross Unrealized Losses | (1,242,000) | (1,661,000)
Fair Value | 25,905,000 | 25,763,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] |  |
Note 6 - Investment Securities Available For Sale (Details) - Amortized Cost and Fair Values of Securities Available for Sale [Line Items] |  |
Amortized Cost | 37,562,000 | 38,816,000
Gross Unrealized Gains | 621,000 | 535,000
Gross Unrealized Losses | (739,000) | (1,028,000)
Fair Value | 37,444,000 | 38,323,000
Mortgage-backed Securities, Issued by Private Enterprises [Member] |  |
Note 6 - Investment Securities Available For Sale (Details) - Amortized Cost and Fair Values of Securities Available for Sale [Line Items] |  |
Amortized Cost | 3,172,000 | 3,366,000
Gross Unrealized Gains | 304,000 | 327,000
Fair Value | 3,476,000 | 3,693,000
Debt Securities [Member] |  |
Note 6 - Investment Securities Available For Sale (Details) - Amortized Cost and Fair Values of Securities Available for Sale [Line Items] |  |
Amortized Cost | 155,777,000 | 159,782,000
Gross Unrealized Gains | 3,625,000 | 2,605,000
Gross Unrealized Losses | (4,218,000) | (5,994,000)
Fair Value | 155,184,000 | 156,393,000
Equity Securities in Financial Institutions [Member] |  |
Note 6 - Investment Securities Available For Sale (Details) - Amortized Cost and Fair Values of Securities Available for Sale [Line Items] |  |
Amortized Cost | 750,000 | 750,000
Gross Unrealized Gains | 6,000 |
Fair Value | $ 756,000 | $ 750,000

X
- Details
Name: | mbcn_Note6InvestmentSecuritiesAvailableForSaleDetailsAmortizedCostandFairValuesofSecuritiesAvailableforSaleLineItems
Namespace Prefix: | mbcn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 + Details
Name: | us-gaap_AvailableForSaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.2) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_AvailableForSaleSecuritiesAmortizedCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of unrealized gain before deducting unrealized loss on investments in debt and equity securities classified as available-for-sale securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration