XML 102 R66.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Loans and Allowance for Loan Losses - Allowance Related to Loans Categorized as Troubled Debt Restructurings (Detail) (USD $) | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2010
--- | --- | --- | --- | ---
Schedule Of Financing Receivable Troubled Debt Restructurings [Line Items] |  |  |  |
Total | $ 22,821,000 | $ 28,677,000 | $ 36,532,000 | $ 45,368,000
Commercial Loans [Member] |  |  |  |
Schedule Of Financing Receivable Troubled Debt Restructurings [Line Items] |  |  |  |
Total | 20,455,000 | 26,043,000 | 33,431,000 | 42,359,000
Retail Loans [Member] |  |  |  |
Schedule Of Financing Receivable Troubled Debt Restructurings [Line Items] |  |  |  |
Total | 2,358,000 | 2,645,000 | 3,019,000 | 2,972,000
Financing Receivable Troubled Debt Restructuring [Member] |  |  |  |
Schedule Of Financing Receivable Troubled Debt Restructurings [Line Items] |  |  |  |
Total | 10,351,000 | 13,097,000 |  |
Financing Receivable Troubled Debt Restructuring [Member] | Commercial and Industrial [Member] |  |  |  |
Schedule Of Financing Receivable Troubled Debt Restructurings [Line Items] |  |  |  |
Total | 187,000 | 772,000 |  |
Financing Receivable Troubled Debt Restructuring [Member] | Commercial Vacant Land, Land Development, and Residential Construction [Member] |  |  |  |
Schedule Of Financing Receivable Troubled Debt Restructurings [Line Items] |  |  |  |
Total | 798,000 | 713,000 |  |
Financing Receivable Troubled Debt Restructuring [Member] | Commercial Real Estate - Owner Occupied [Member] |  |  |  |
Schedule Of Financing Receivable Troubled Debt Restructurings [Line Items] |  |  |  |
Total | 528,000 | 1,116,000 |  |
Financing Receivable Troubled Debt Restructuring [Member] | Commercial Real Estate - Non-Owner Occupied [Member] |  |  |  |
Schedule Of Financing Receivable Troubled Debt Restructurings [Line Items] |  |  |  |
Total | 7,828,000 | 9,751,000 |  |
Financing Receivable Troubled Debt Restructuring [Member] | Commercial Real Estate - Multi-Family and Residential Rental [Member] |  |  |  |
Schedule Of Financing Receivable Troubled Debt Restructurings [Line Items] |  |  |  |
Total | 1,010,000 | 745,000 |  |
Financing Receivable Troubled Debt Restructuring [Member] | Commercial Loans [Member] |  |  |  |
Schedule Of Financing Receivable Troubled Debt Restructurings [Line Items] |  |  |  |
Total | 10,351,000 | 13,097,000 |  |
Financing Receivable Troubled Debt Restructuring [Member] | Home equity and other [Member] |  |  |  |
Schedule Of Financing Receivable Troubled Debt Restructurings [Line Items] |  |  |  |
Total | 0 | 0 |  |
Financing Receivable Troubled Debt Restructuring [Member] | 1 - 4 family mortgages [Member] |  |  |  |
Schedule Of Financing Receivable Troubled Debt Restructurings [Line Items] |  |  |  |
Total | 0 | 0 |  |
Financing Receivable Troubled Debt Restructuring [Member] | Retail Loans [Member] |  |  |  |
Schedule Of Financing Receivable Troubled Debt Restructurings [Line Items] |  |  |  |
Total | $ 0 | $ 0 |  |

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

X
- Definition A valuation allowance for financing receivables that are expected to be uncollectible. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant