XML 68 R37.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Loans and Allowance for Loan Losses (Details) (USD $) | Jun. 30, 2013 | Dec. 31, 2012 | Jun. 30, 2012
--- | --- | --- | ---
Components of loan portfolio disaggregated by class of loan and percentage change in total loans |  |  |
Total loans | $ 1,058,662,000 | $ 1,041,189,000 | $ 1,060,996,000
Loan portfolio classes and segments as a percentage of aggregate loans | 100.00% | 100.00% |
Loans and leases receivable net of deferred income increase decrease percentage | 1.70% |  |
Commercial and industrial [Member] |  |  |
Components of loan portfolio disaggregated by class of loan and percentage change in total loans |  |  |
Total loans | 279,300,000 | 285,322,000 |
Loan portfolio classes and segments as a percentage of aggregate loans | 26.40% | 27.40% |
Loans and leases receivable net of deferred income increase decrease percentage | (2.10%) |  |
Vacant land, land development, and residential construction [Member] |  |  |
Components of loan portfolio disaggregated by class of loan and percentage change in total loans |  |  |
Total loans | 42,170,000 | 48,099,000 |
Loan portfolio classes and segments as a percentage of aggregate loans | 4.00% | 4.60% |
Loans and leases receivable net of deferred income increase decrease percentage | (12.30%) |  |
Real estate - owner occupied [Member] |  |  |
Components of loan portfolio disaggregated by class of loan and percentage change in total loans |  |  |
Total loans | 253,172,000 | 259,277,000 |
Loan portfolio classes and segments as a percentage of aggregate loans | 23.90% | 24.90% |
Loans and leases receivable net of deferred income increase decrease percentage | (2.40%) |  |
Real estate - non-owner occupied [Member] |  |  |
Components of loan portfolio disaggregated by class of loan and percentage change in total loans |  |  |
Total loans | 357,452,000 | 324,886,000 |
Loan portfolio classes and segments as a percentage of aggregate loans | 33.80% | 31.20% |
Loans and leases receivable net of deferred income increase decrease percentage | 10.00% |  |
Real estate - multi-family and residential rental [Member] |  |  |
Components of loan portfolio disaggregated by class of loan and percentage change in total loans |  |  |
Total loans | 53,522,000 | 50,922,000 |
Loan portfolio classes and segments as a percentage of aggregate loans | 5.00% | 4.90% |
Loans and leases receivable net of deferred income increase decrease percentage | 5.10% |  |
Total commercial [Member] |  |  |
Components of loan portfolio disaggregated by class of loan and percentage change in total loans |  |  |
Total loans | 985,616,000 | 968,506,000 | 987,491,000
Loan portfolio classes and segments as a percentage of aggregate loans | 93.10% | 93.00% |
Loans and leases receivable net of deferred income increase decrease percentage | 1.80% |  |
Retail Home equity and other [Member] |  |  |
Components of loan portfolio disaggregated by class of loan and percentage change in total loans |  |  |
Total loans | 37,337,000 | 38,917,000 |
Loan portfolio classes and segments as a percentage of aggregate loans | 3.50% | 3.70% |
Loans and leases receivable net of deferred income increase decrease percentage | (4.10%) |  |
Retail 1-4 family mortgages [Member] |  |  |
Components of loan portfolio disaggregated by class of loan and percentage change in total loans |  |  |
Total loans | 35,709,000 | 33,766,000 |
Loan portfolio classes and segments as a percentage of aggregate loans | 3.40% | 3.30% |
Loans and leases receivable net of deferred income increase decrease percentage | 5.80% |  |
Total retail [Member] |  |  |
Components of loan portfolio disaggregated by class of loan and percentage change in total loans |  |  |
Total loans | $ 73,046,000 | $ 72,683,000 | $ 73,505,000
Loan portfolio classes and segments as a percentage of aggregate loans | 6.90% | 7.00% |
Loans and leases receivable net of deferred income increase decrease percentage | 0.50% |  |

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

X
- Definition Loan portfolio classes and segments as a percentage of aggregate loans. + References No definition available. + Details
Name: | mbwm_LoanPortfolioClassesAndSegmentsAsPercentageOfAggregateLoans
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Loans and leases receivable net of deferred income increase decrease percentage. + References No definition available. + Details
Name: | mbwm_LoansAndLeasesReceivableNetOfDeferredIncomeIncreaseDecreasePercentage
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5074-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522 + Details
Name: | us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant