XML 51 R36.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Note 2 - Business Combination (Details) - Pro Forma Information (Firstbank Corporation [Member], USD $) | 3 Months Ended
--- | ---
Mar. 31, 2014
Firstbank Corporation [Member] |
Note 2 - Business Combination (Details) - Pro Forma Information [Line Items] |
Net interest income | $ 23,883,000 mbwm_BusinessAcquisitionsProFormaNetInterestIncome / us-gaap_BusinessAcquisitionAxis = mbwm_FirstbankCorporationMember
Noninterest expense | 20,018,000 mbwm_BusinessAcquisitionsProFormaNoninterestExpense / us-gaap_BusinessAcquisitionAxis = mbwm_FirstbankCorporationMember
Net income | $ 6,395,000 us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss / us-gaap_BusinessAcquisitionAxis = mbwm_FirstbankCorporationMember
Net income per diluted share (in Dollars per share) | $ 0.38 us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted / us-gaap_BusinessAcquisitionAxis = mbwm_FirstbankCorporationMember

X
- Definition The pro forma net interest Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period. + References No definition available. + Details
Name: | mbwm_BusinessAcquisitionsProFormaNetInterestIncome
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The pro forma noninterest expense for the period as if the business combination or combinations had been completed at the beginning of a period. + References No definition available. + Details
Name: | mbwm_BusinessAcquisitionsProFormaNoninterestExpense
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | mbwm_Note2BusinessCombinationDetailsProFormaInformationLineItems
Namespace Prefix: | mbwm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(2)-(3) -URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463 + Details
Name: | us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(2)-(3) -URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463 + Details
Name: | us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration