XML 21 R73.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Note 13 - Regulatory Matters (Details) (USD $) | 0 Months Ended | 3 Months Ended | 9 Months Ended |  |  | 0 Months Ended
--- | --- | --- | --- | --- | --- | ---
Sep. 24, 2014 | Jun. 25, 2014 | May 29, 2014 | Mar. 10, 2014 | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Dec. 31, 2013 | Dec. 31, 2009 | Oct. 16, 2014 Subsequent Event [Member]
Note 13 - Regulatory Matters (Details) [Line Items] |  |  |  |  |  |  |  |  |  |  |
Trust Preferred Securities Included in Tier One Capital (in Dollars) |  |  |  |  | $ 52,200,000 |  | $ 52,200,000 |  | $ 32,000,000 |  |
Maximum Restricted Core Element Allowed in Tier One Capital, Percent |  |  |  |  |  |  | 25.00% |  |  |  |
Maximum Level of Consolidated Aggregate Assets Allowing for Inclusion of Trust Preferred Securities in Tier One Capital (in Dollars) |  |  |  |  |  |  |  |  |  | $ 15,000,000,000 |
Common Stock, Dividends, Per Share, Cash Paid | $ 0.12 | $ 0.12 | $ 2.00 | $ 0.12 | $ 0.12 | $ 0.12 | $ 2.36 | $ 0.33 |  |  |
Common Stock, Dividends, Per Share, Declared |  |  |  |  |  |  |  |  |  |  | $ 0.12

X
- Definition The maximum level of consolidated aggregate assets allowing for inclusion of trust preferred securities in Tier 1 Capital under the Dodd-Frank Act. + References No definition available. + Details
Name: | mbwm_MaximumLevelOfConsolidatedAggregateAssetsAllowingForInclusionOfTrustPreferredSecuritiesInTierOneCapital
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The maximum amount of restricted core elements allowed in tier one capital expressed as a percent. + References No definition available. + Details
Name: | mbwm_MaximumRestrictedCoreElementAllowedInTierOneCapitalPercent
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | mbwm_Note13RegulatoryMattersDetailsLineItems
Namespace Prefix: | mbwm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Trust preferred securities held by the trust that are included in Tier One Capital and subject to certain limitations. + References No definition available. + Details
Name: | mbwm_TrustPreferredSecuritiesIncludedInTierOneCapital
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Aggregate dividends paid during the period for each share of common stock outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_CommonStockDividendsPerShareCashPaid
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate dividends declared during the period for each share of common stock outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration