XML 38 R28.htm IDEA: XBRL DOCUMENT
v3.21.2

Note 8 - Commitments and Off-balance Sheet Risk (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2021
Notes Tables |
Summary of Contractual Amounts of Financial Instruments With Off Balance Sheet Risk [Table Text Block] |
|  | June 30, 2021 |  |  | December 31, 2020 |
Commercial unused lines of credit |  | $ | 1,112,887,000 |  |  | $ | 1,019,496,000 |
Unused lines of credit secured by 1 – 4 family residential properties |  |  | 60,021,000 |  |  |  | 59,396,000 |
Credit card unused lines of credit |  |  | 81,190,000 |  |  |  | 72,495,000 |
Other consumer unused lines of credit |  |  | 54,540,000 |  |  |  | 30,707,000 |
Commitments to make loans |  |  | 161,227,000 |  |  |  | 227,558,000 |
Standby letters of credit |  |  | 26,234,000 |  |  |  | 20,543,000 |
|  | $ | 1,496,099,000 |  |  | $ | 1,430,195,000 |

X
- Definition Tabular disclosure of contractual amounts of financial instruments with off-balance sheet risk. + References No definition available. + Details
Name: | mbwm_SummaryOfContractualAmountsOfFinancialInstrumentsWithOffBalanceSheetRiskTableTextBlock
Namespace Prefix: | mbwm_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

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