XML 37 R27.htm IDEA: XBRL DOCUMENT
v3.4.0.3

Note 7 - Federal Home Loan Bank Advances (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2016
Disclosure Text Block [Abstract] |
Maturities of Currently Outstanding FHLB Advances [Table Text Block] |
2016 |  | $ | 3,000,000 |
2017 |  |  | 45,000,000 |
2018 |  |  | 0 |
2019 |  |  | 10,000,000 |
2020 |  |  | 10,000,000 |
Thereafter |  |  | 30,000,000 |

X
- Definition Tabular disclosure of the maturities of currently outstanding Federal Home Loan Bank advances. + References No definition available. + Details
Name: | mbwm_MaturitiesOfCurrentlyOutstandingFHLBAdvancesTableTextBlock
Namespace Prefix: | mbwm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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