XML 122 R108.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Note 13 - Related Parties (Details) - USD ($) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Note 13 - Related Parties (Details) [Line Items] |  |  |
Related Party Deposits and Repurchase Agreements | $ 18,500,000 | $ 16,600,000 |
Directors and Executive Officers [Member] |  |  |
Note 13 - Related Parties (Details) [Line Items] |  |  |
Loan Commitments to Related Parties | 14,000,000 | 15,800,000 |
Loans and Leases Receivable, Related Parties | $ 11,151,000 | $ 9,002,000 | $ 6,884,000

X
- Definition Represents the amount of loan commitments to related parties of the Company. + References No definition available. + Details
Name: | mbwm_LoanCommitmentsToRelatedParties
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | mbwm_Note13RelatedPartiesDetailsLineItems
Namespace Prefix: | mbwm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the balances of related party deposits and repurchase agreements. + References No definition available. + Details
Name: | mbwm_RelatedPartyDepositsAndRepurchaseAgreements
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition For an unclassified balance sheet, reflects the carrying amount of unpaid loan amounts due from related parties at the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(e)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 + Details
Name: | us-gaap_LoansAndLeasesReceivableRelatedParties
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=mbwm_DirectorsAndExecutiveOfficersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |