XML 29 R73.htm IDEA: XBRL DOCUMENT v2.4.1.9
Note 9 - Short-term Borrowings (Details) - Outstanding Balances and Related Information of Short-term Borrowings (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Short-term Debt [Line Items]    
Balance at year-end $ 14,808us-gaap_ShortTermBorrowings $ 10,809us-gaap_ShortTermBorrowings
Average balance outstanding 8,379mbcn_ShortTermBorrowingsAverageBalanceOutstanding 8,806mbcn_ShortTermBorrowingsAverageBalanceOutstanding
Maximum month-end balance $ 19,970mbcn_ShortTermBorrowingsMaximumMonthendBalance $ 17,351mbcn_ShortTermBorrowingsMaximumMonthendBalance
Year End [Member]    
Short-term Debt [Line Items]    
Weighted-average rate 0.98%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_ShortTermDebtTypeAxis
= mbcn_YearEndMember		 1.44%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_ShortTermDebtTypeAxis
= mbcn_YearEndMember
During the Year [Member]    
Short-term Debt [Line Items]    
Weighted-average rate 1.77%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_ShortTermDebtTypeAxis
= mbcn_DuringTheYearMember		 3.15%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_ShortTermDebtTypeAxis
= mbcn_DuringTheYearMember