XML 73 R63.htm IDEA: XBRL DOCUMENT
v3.19.1

Note 11 - Fair Values - Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - Fair Value, Nonrecurring [Member] - USD ($) | Mar. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Impaired loans | $ 8,757,000 | $ 8,181,000
Foreclosed assets | 396,000 | 811,000
Total | 9,153,000 | 8,992,000
Fair Value, Inputs, Level 1 [Member] |  |
Impaired loans | 0 | 0
Foreclosed assets | 0 | 0
Total | 0 | 0
Fair Value, Inputs, Level 2 [Member] |  |
Impaired loans | 0 | 0
Foreclosed assets | 0 | 0
Total | 0 | 0
Fair Value, Inputs, Level 3 [Member] |  |
Impaired loans | 8,757,000 | 8,181,000
Foreclosed assets | 396,000 | 811,000
Total | $ 9,153,000 | $ 8,992,000

X
- Definition The fair value disclosure of foreclosed assets held by the company. + References No definition available. + Details
Name: | mbwm_ForeclosedAssetsFairValueDisclosure
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The fair value disclosure of impaired loans held by the company. + References No definition available. + Details
Name: | mbwm_ImpairedLoansFairValueDisclosure
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |