XML 64 R60.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Note 8 - Commitments and Off-Balance Sheet Risk (Details) (USD $) |  |  |  | 3 Months Ended
--- | --- | --- | --- | ---
Mar. 31, 2014 | Mar. 31, 2013 | Mar. 31, 2014 Interest Rate Swap Agreement [Member] | Mar. 31, 2014 Minimum [Member] | Mar. 31, 2014 Maximum [Member]
Note 8 - Commitments and Off-Balance Sheet Risk (Details) [Line Items] |  |  |  |  |
Reserve Or Liability Balance For Financial Instruments With Off Balance Sheet Risk | $ 0 | $ 0 |  |  |
Derivative, Notional Amount |  |  | 17,800,000 |  |
Derivative, Fair Value, Net | $ (2,500,000) |  |  |  |
Fees Accreted Into Income During Interest Rate Swap Agreements Term |  |  |  | 4 years | 15 years

X
- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
Name: | invest_DerivativeNotionalAmount
Namespace Prefix: | invest_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition The fees accreted into income during interest rate swap agreement years. + References No definition available. + Details
Name: | mbwm_FeesAccretedIntoIncomeDuringInterestRateSwapAgreementsTerm
Namespace Prefix: | mbwm_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | mbwm_Note8CommitmentsandOffBalanceSheetRiskDetailsLineItems
Namespace Prefix: | mbwm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Reserve or liability balance for financial instruments with off balance sheet risk + References No definition available. + Details
Name: | mbwm_ReserveOrLiabilityBalanceForFinancialInstrumentsWithOffBalanceSheetRisk
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value of the assets less the liabilities of a derivative or group of derivatives. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13433-108611 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13495-108611 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant