$MBWM
Mercantile Bank Corp Stock $mbwm

$mbwm Overview Financials Valuation SEC Filings Company Website

2021 Q4 Form 10-K Financial Statement

#000143774922005284 Filed on March 04, 2022

Income Statement

Concept	2021 Q4	2021 Q3	2021 Q2
Revenue	$37.05M	$35.89M	$35.77M
YoY Change	-1.53%	0.83%	-3.74%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$3.480M	$1.500M	$1.400M
YoY Change	9.78%	15.38%	7.69%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense		$4.764M	$4.903M
YoY Change		-21.71%	-25.63%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$15.22M	$18.58M	$22.34M
YoY Change	-14.21%	40.85%	107.98%
Income Tax	$3.580M	$3.531M	$4.244M
% Of Pretax Income	23.52%	19.0%	19.0%
Net Earnings	$11.64M	$15.05M	$18.09M
YoY Change	-17.35%	40.85%	108.01%
Net Earnings / Revenue	31.42%	41.94%	50.57%
Basic Earnings Per Share	$0.74	$0.95	$1.12
Diluted Earnings Per Share	$0.74	$0.95	$1.12
COMMON SHARES
Basic Shares Outstanding	15.67M	15.86M	16.12M
Diluted Shares Outstanding		15.86M	16.12M

Balance Sheet

Concept	2021 Q4	2021 Q3	2021 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$975.2M
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$57.30M	$57.47M	$58.25M
YoY Change	-2.82%	-4.93%	-1.53%
Goodwill	$49.47M	$49.47M	$49.47M
YoY Change	0.0%	0.0%	0.0%
Intangibles
YoY Change
Long-Term Investments
YoY Change
Other Assets
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$5.258B	$4.964B	$4.757B
YoY Change	18.49%	12.3%	10.27%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$24.60M	$25.20M	$22.60M
YoY Change	1.23%	37.7%	24.86%
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$197.5M	$175.9M	$169.7M
YoY Change	66.81%	12.04%	1.31%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$24.60M	$25.20M	$22.60M
YoY Change	1.23%	37.7%	24.86%
LONG-TERM LIABILITIES
Long-Term Debt	$121.9M	$48.10M	$47.90M
YoY Change	156.09%	1.48%	1.48%
Other Long-Term Liabilities
YoY Change
Total Long-Term Liabilities	$121.9M	$48.10M	$47.90M
YoY Change	156.09%	1.48%	1.48%
TOTAL LIABILITIES
Total Short-Term Liabilities	$24.60M	$25.20M	$22.60M
Total Long-Term Liabilities	$121.9M	$48.10M	$47.90M
Total Liabilities	$4.801B	$4.512B	$4.306B
YoY Change	20.16%	13.12%	10.71%
SHAREHOLDERS EQUITY
Retained Earnings	$174.5M	$167.5M	$157.2M
YoY Change	30.21%	34.62%	32.91%
Common Stock	$285.8M	$285.0M	$293.2M
YoY Change	-5.39%	-5.59%	-2.55%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$456.6M	$452.3M	$451.9M
YoY Change
Total Liabilities & Shareholders Equity	$5.258B	$4.964B	$4.757B
YoY Change	18.49%	12.3%	10.27%

Cashflow Statement

Concept	2021 Q4	2021 Q3	2021 Q2
OPERATING ACTIVITIES
Net Income	$11.64M	$15.05M	$18.09M
YoY Change	-17.35%	40.85%	108.01%
Depreciation, Depletion And Amortization	$3.480M	$1.500M	$1.400M
YoY Change	9.78%	15.38%	7.69%
Cash From Operating Activities	$45.40M	-$3.010M	$23.60M
YoY Change	110.48%	-110.49%	-1004.21%
INVESTING ACTIVITIES
Capital Expenditures	-$1.350M	-$690.0K	-$1.960M
YoY Change	-24.58%	-75.09%	54.33%
Acquisitions
YoY Change
Other Investing Activities	-$177.7M	-$121.0M	$45.12M
YoY Change	-421.08%	222.21%	-111.05%
Cash From Investing Activities	-$179.1M	-$121.7M	$43.18M
YoY Change	-434.34%	201.81%	-110.54%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	283.5M	190.5M	40.42M
YoY Change	-7720.16%	100.57%	-93.75%
NET CHANGE
Cash From Operating Activities	45.40M	-3.010M	23.60M
Cash From Investing Activities	-179.1M	-121.7M	43.18M
Cash From Financing Activities	283.5M	190.5M	40.42M
Net Change In Cash	149.8M	65.82M	107.2M
YoY Change	109.77%	-21.05%	-54.29%
FREE CASH FLOW
Cash From Operating Activities	$45.40M	-$3.010M	$23.60M
Capital Expenditures	-$1.350M	-$690.0K	-$1.960M
Free Cash Flow	$46.75M	-$2.320M	$25.56M
YoY Change	100.13%	-107.37%	-2007.46%

Facts In Submission

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CY2019	mbwm	Interest Rate Swap Program Fees InterestRateSwapProgramFees	0	USD
CY2021	mbwm	Fees And Commissions Payroll Processing FeesAndCommissionsPayrollProcessing	1815000	USD
CY2020	mbwm	Fees And Commissions Payroll Processing FeesAndCommissionsPayrollProcessing	1745000	USD
CY2019	mbwm	Fees And Commissions Payroll Processing FeesAndCommissionsPayrollProcessing	1626000	USD
CY2021	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	1164000	USD
CY2020	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	1214000	USD
CY2019	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	3886000	USD
CY2021	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	1058000	USD
CY2020	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	USD
CY2019	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	0	USD
CY2021	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	2768000	USD
CY2020	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	1384000	USD
CY2019	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	2450000	USD
CY2021	us-gaap	Noninterest Income NoninterestIncome	56220000	USD
CY2020	us-gaap	Noninterest Income NoninterestIncome	45172000	USD
CY2019	us-gaap	Noninterest Income NoninterestIncome	26956000	USD
CY2021	us-gaap	Labor And Related Expense LaborAndRelatedExpense	66447000	USD
CY2020	us-gaap	Labor And Related Expense LaborAndRelatedExpense	59799000	USD
CY2019	us-gaap	Labor And Related Expense LaborAndRelatedExpense	53833000	USD
CY2021	us-gaap	Occupancy Net OccupancyNet	8088000	USD
CY2020	us-gaap	Occupancy Net OccupancyNet	7950000	USD
CY2019	us-gaap	Occupancy Net OccupancyNet	7061000	USD
CY2021	us-gaap	Equipment Expense EquipmentExpense	3654000	USD
CY2020	us-gaap	Equipment Expense EquipmentExpense	3350000	USD
CY2019	us-gaap	Equipment Expense EquipmentExpense	2583000	USD
CY2021	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	11104000	USD
CY2020	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	10440000	USD
CY2019	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	9235000	USD
CY2021	us-gaap	Advertising Expense AdvertisingExpense	1175000	USD
CY2020	us-gaap	Advertising Expense AdvertisingExpense	1292000	USD
CY2019	us-gaap	Advertising Expense AdvertisingExpense	1446000	USD
CY2021	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	1820000	USD
CY2020	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	1138000	USD
CY2019	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	225000	USD
CY2021	mbwm	Charitable Foundation Contribution Expense CharitableFoundationContributionExpense	4020000	USD
CY2020	mbwm	Charitable Foundation Contribution Expense CharitableFoundationContributionExpense	0	USD
CY2019	mbwm	Charitable Foundation Contribution Expense CharitableFoundationContributionExpense	0	USD
CY2021	us-gaap	Other Noninterest Expense OtherNoninterestExpense	14558000	USD
CY2020	us-gaap	Other Noninterest Expense OtherNoninterestExpense	14551000	USD
CY2019	us-gaap	Other Noninterest Expense OtherNoninterestExpense	14897000	USD
CY2021	us-gaap	Noninterest Expense NoninterestExpense	110866000	USD
CY2020	us-gaap	Noninterest Expense NoninterestExpense	98520000	USD
CY2019	us-gaap	Noninterest Expense NoninterestExpense	89280000	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	73716000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	54848000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	60460000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14695000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	10710000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	11004000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	59021000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	44138000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	49456000	USD
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.69
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.71
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.01
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.69
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.71
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.01
CY2021	us-gaap	Net Income Loss NetIncomeLoss	59021000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	44138000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	49456000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-11664000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	2268000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	15106000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	-11664000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	2268000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	15106000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-2449000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	477000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	3172000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-2449000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	477000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	3172000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-9215000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	1791000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	11934000	USD
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	49806000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	45929000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	61390000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	375249000	USD
CY2019	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	50000	USD
CY2019	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	729000	USD
CY2019	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	128000	USD
CY2019	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	375000	USD
CY2019	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	2931000	USD
CY2019	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	7183000	USD
CY2019	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	17108000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	49456000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	11934000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	416561000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	416561000	USD
CY2020	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	49000	USD
CY2020	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	814000	USD
CY2020	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	3000	USD
CY2020	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	394000	USD
CY2020	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	2325000	USD
CY2020	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	6591000	USD
CY2020	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	17930000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	44138000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	1791000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	441554000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	441554000	USD
CY2021	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	48000	USD
CY2021	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	877000	USD
CY2021	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	50000	USD
CY2021	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	344000	USD
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	3784000	USD
CY2021	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	21380000	USD
CY2021	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	18524000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	59021000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-9215000	USD
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	456559000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	59021000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	44138000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	49456000	USD
CY2021	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	13678000	USD
CY2020	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	9425000	USD
CY2019	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	9553000	USD
CY2021	mbwm	Discount Accretion On Acquired Loans DiscountAccretionOnAcquiredLoans	135000	USD
CY2020	mbwm	Discount Accretion On Acquired Loans DiscountAccretionOnAcquiredLoans	449000	USD
CY2019	mbwm	Discount Accretion On Acquired Loans DiscountAccretionOnAcquiredLoans	686000	USD
CY2021	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-4300000	USD
CY2020	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	14050000	USD
CY2019	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1750000	USD
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	2020000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-4141000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	26000	USD
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	3784000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	2325000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	2931000	USD
CY2021	us-gaap	Issuance Of Stock And Warrants For Services Or Claims IssuanceOfStockAndWarrantsForServicesOrClaims	344000	USD
CY2020	us-gaap	Issuance Of Stock And Warrants For Services Or Claims IssuanceOfStockAndWarrantsForServicesOrClaims	394000	USD
CY2019	us-gaap	Issuance Of Stock And Warrants For Services Or Claims IssuanceOfStockAndWarrantsForServicesOrClaims	375000	USD
CY2021	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	686418000	USD
CY2020	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	677634000	USD
CY2019	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	261021000	USD
CY2021	us-gaap	Payments For Origination Of Mortgage Loans Held For Sale PaymentsForOriginationOfMortgageLoansHeldForSale	649245000	USD
CY2020	us-gaap	Payments For Origination Of Mortgage Loans Held For Sale PaymentsForOriginationOfMortgageLoansHeldForSale	665992000	USD
CY2019	us-gaap	Payments For Origination Of Mortgage Loans Held For Sale PaymentsForOriginationOfMortgageLoansHeldForSale	256767000	USD
CY2021	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	30402000	USD
CY2020	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	29541000	USD
CY2019	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	8108000	USD
CY2021	mbwm	Net Gain Loss From Sale And Valuation Write Down Of Foreclosed Assets NetGainLossFromSaleAndValuationWriteDownOfForeclosedAssets	78000	USD
CY2020	mbwm	Net Gain Loss From Sale And Valuation Write Down Of Foreclosed Assets NetGainLossFromSaleAndValuationWriteDownOfForeclosedAssets	325000	USD
CY2019	mbwm	Net Gain Loss From Sale And Valuation Write Down Of Foreclosed Assets NetGainLossFromSaleAndValuationWriteDownOfForeclosedAssets	254000	USD
CY2021	mbwm	Net Gain Loss From Sale And Valuation Write Down Of Former Bank Premises NetGainLossFromSaleAndValuationWriteDownOfFormerBankPremises	140000	USD
CY2020	mbwm	Net Gain Loss From Sale And Valuation Write Down Of Former Bank Premises NetGainLossFromSaleAndValuationWriteDownOfFormerBankPremises	27000	USD
CY2019	mbwm	Net Gain Loss From Sale And Valuation Write Down Of Former Bank Premises NetGainLossFromSaleAndValuationWriteDownOfFormerBankPremises	436000	USD
CY2021	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-246000	USD
CY2020	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-1514000	USD
CY2019	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-294000	USD
CY2021	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	1164000	USD
CY2020	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	1214000	USD
CY2019	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	3886000	USD
CY2021	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	1058000	USD
CY2020	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	-0	USD
CY2019	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	-0	USD
CY2021	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	-1528000	USD
CY2020	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	917000	USD
CY2019	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	48000	USD
CY2021	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	16279000	USD
CY2020	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	10892000	USD
CY2019	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	7636000	USD
CY2021	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	335000	USD
CY2020	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	1895000	USD
CY2019	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	-2818000	USD
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	64573000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	37877000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	44767000	USD
CY2021	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	298708000	USD
CY2020	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	369682000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	62084000	USD
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	80432000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	321164000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	79478000	USD
CY2021	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	-0	USD
CY2020	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	-0	USD
CY2019	us-gaap	Payments To Acquire Federal Home Loan Bank Stock PaymentsToAcquireFederalHomeLoanBankStock	1980000	USD
CY2021	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	267899000	USD
CY2020	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	341461000	USD
CY2019	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	99620000	USD
CY2021	us-gaap	Payments To Acquire Life Insurance Policies PaymentsToAcquireLifeInsurancePolicies	2000000	USD
CY2020	us-gaap	Payments To Acquire Life Insurance Policies PaymentsToAcquireLifeInsurancePolicies	700000	USD
CY2019	us-gaap	Payments To Acquire Life Insurance Policies PaymentsToAcquireLifeInsurancePolicies	4500000	USD
CY2021	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	0	USD
CY2020	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	0	USD
CY2019	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	7708000	USD
CY2021	us-gaap	Payments For Proceeds From Businesses And Interest In Affiliates PaymentsForProceedsFromBusinessesAndInterestInAffiliates	2679000	USD
CY2020	us-gaap	Payments For Proceeds From Businesses And Interest In Affiliates PaymentsForProceedsFromBusinessesAndInterestInAffiliates	-0	USD
CY2019	us-gaap	Payments For Proceeds From Businesses And Interest In Affiliates PaymentsForProceedsFromBusinessesAndInterestInAffiliates	-0	USD
CY2021	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	5602000	USD
CY2020	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	8989000	USD
CY2019	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	13484000	USD
CY2021	mbwm	Proceeds From Sale Of Former Bank Premises ProceedsFromSaleOfFormerBankPremises	753000	USD
CY2021	us-gaap	Interest Paid Net InterestPaidNet	20352000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	27703000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	32103000	USD
CY2021	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	17550000	USD
CY2020	mbwm	Proceeds From Sale Of Former Bank Premises ProceedsFromSaleOfFormerBankPremises	162000	USD
CY2019	mbwm	Proceeds From Sale Of Former Bank Premises ProceedsFromSaleOfFormerBankPremises	854000	USD
CY2021	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	196000	USD
CY2020	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	700000	USD
CY2019	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	790000	USD
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-495507000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-398806000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-92838000	USD
CY2021	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	-120512000	USD
CY2020	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	-99294000	USD
CY2019	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	170921000	USD
CY2021	us-gaap	Increase Decrease In Other Deposits IncreaseDecreaseInOtherDeposits	806796000	USD
CY2020	us-gaap	Increase Decrease In Other Deposits IncreaseDecreaseInOtherDeposits	820463000	USD
CY2019	us-gaap	Increase Decrease In Other Deposits IncreaseDecreaseInOtherDeposits	55755000	USD
CY2021	us-gaap	Proceeds From Payments For In Securities Sold Under Agreements To Repurchase ProceedsFromPaymentsForInSecuritiesSoldUnderAgreementsToRepurchase	79098000	USD
CY2020	us-gaap	Proceeds From Payments For In Securities Sold Under Agreements To Repurchase ProceedsFromPaymentsForInSecuritiesSoldUnderAgreementsToRepurchase	15690000	USD
CY2019	us-gaap	Proceeds From Payments For In Securities Sold Under Agreements To Repurchase ProceedsFromPaymentsForInSecuritiesSoldUnderAgreementsToRepurchase	-844000	USD
CY2021	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	0	USD
CY2020	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	60000000	USD
CY2019	us-gaap	Proceeds From Federal Home Loan Bank Borrowings ProceedsFromFederalHomeLoanBankBorrowings	44000000	USD
CY2021	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	20000000	USD
CY2020	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	20000000	USD
CY2019	us-gaap	Repayments Of Federal Home Loan Bank Borrowings RepaymentsOfFederalHomeLoanBankBorrowings	40000000	USD
CY2021	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	73635000	USD
CY2020	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	0	USD
CY2019	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	0	USD
CY2021	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	50000	USD
CY2020	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	3000	USD
CY2019	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	128000	USD
CY2021	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	48000	USD
CY2020	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	49000	USD
CY2019	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	50000	USD
CY2021	us-gaap	Proceeds From Issuance Of Common Stock Dividend Reinvestment Plan ProceedsFromIssuanceOfCommonStockDividendReinvestmentPlan	877000	USD
CY2020	us-gaap	Proceeds From Issuance Of Common Stock Dividend Reinvestment Plan ProceedsFromIssuanceOfCommonStockDividendReinvestmentPlan	814000	USD
CY2019	us-gaap	Proceeds From Issuance Of Common Stock Dividend Reinvestment Plan ProceedsFromIssuanceOfCommonStockDividendReinvestmentPlan	729000	USD
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	21380000	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	6591000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	7183000	USD
CY2021	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	18524000	USD
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	17930000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	17108000	USD
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	780088000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	753204000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	206448000	USD
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	349154000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	392275000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	158377000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	626006000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	233731000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	75354000	USD
CY2021Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	975160000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	626006000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	233731000	USD
CY2020	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	10950000	USD
CY2019	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	11975000	USD
CY2021	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	30000	USD
CY2020	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	146000	USD
CY2019	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	337000	USD
CY2021	mbwm	Transfer Of Bank Premises To Other Real Estate Owned TransferOfBankPremisesToOtherRealEstateOwned	0	USD
CY2020	mbwm	Transfer Of Bank Premises To Other Real Estate Owned TransferOfBankPremisesToOtherRealEstateOwned	613000	USD
CY2019	mbwm	Transfer Of Bank Premises To Other Real Estate Owned TransferOfBankPremisesToOtherRealEstateOwned	258000	USD
CY2021	us-gaap	Use Of Estimates UseOfEstimates	<p style="font-family:Times New Roman;font-size:10pt;font-variant:normal;margin:0pt;"><span style="text-decoration: underline; ">Use of Estimates</span>: To prepare financial statements in conformity with accounting principles generally accepted in the United States of America, management makes estimates and assumptions based on available information. These estimates and assumptions affect the amounts reported in the financial statements and the disclosures provided, and actual results could differ. The allowance for loan losses and the fair values of financial instruments are particularly subject to change.</p> <p style="font-family:'Times New Roman';font-size:10pt;font-variant:normal;margin:0pt;"> </p>
CY2021Q4	us-gaap	Loans And Leases Receivable Deferred Income LoansAndLeasesReceivableDeferredIncome	2500000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Deferred Income LoansAndLeasesReceivableDeferredIncome	4400000	USD
CY2021	mbwm	Interest Income On Commercial And Mortgage Loans Discontinued Period InterestIncomeOnCommercialAndMortgageLoansDiscontinuedPeriod	P90D
CY2021	mbwm	Maximum Delinquency Period For Consumer And Credit Card Loans To Be Charged Off MaximumDelinquencyPeriodForConsumerAndCreditCardLoansToBeChargedOff	P120D
CY2021Q4	us-gaap	Foreclosed Assets ForeclosedAssets	0	USD
CY2020Q4	us-gaap	Foreclosed Assets ForeclosedAssets	700000	USD
CY2021	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	<p style="font-family:Times New Roman;font-size:10pt;font-variant:normal;margin:0pt;"><span style="text-decoration: underline; ">Reclassifications: </span>Certain items in the prior years’ financial statements have been reclassified to conform to the current year presentation.</p> <p style="font-family:'Times New Roman';font-size:10pt;font-variant:normal;margin:0pt;"> </p>
CY2021Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	597463000	USD
CY2021Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	5238000	USD
CY2021Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	9958000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	592743000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	380403000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	7843000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	899000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	387347000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	351062000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	6455000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	110491000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	3503000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	461553000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	9958000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	119073000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	899000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	0	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	0	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	119073000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	899000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	333	pure
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	462000000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	10000000.0	USD
CY2021Q4	us-gaap	Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld	0	USD
CY2021Q4	mbwm	Weighted Average Yield Of Securities Portfolio Due In One Year Or Less WeightedAverageYieldOfSecuritiesPortfolioDueInOneYearOrLess	0.0192	pure
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	11406000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	11458000	USD
CY2021Q4	mbwm	Weighted Average Yield Of Securities Portfolio Due From One To Five Years WeightedAverageYieldOfSecuritiesPortfolioDueFromOneToFiveYears	0.0096	pure
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	185889000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	184788000	USD
CY2021Q4	mbwm	Weighted Average Yield Of Securities Portfolio Due From Five To Ten Years WeightedAverageYieldOfSecuritiesPortfolioDueFromFiveToTenYears	0.0156	pure
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	288599000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	285609000	USD
CY2021Q4	mbwm	Weighted Average Yield Of Securities Portfolio Due Afterten Years WeightedAverageYieldOfSecuritiesPortfolioDueAftertenYears	0.0199	pure
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	69163000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	68585000	USD
CY2021Q4	mbwm	Weighted Average Yield Of Securities Portfolio WeightedAverageYieldOfSecuritiesPortfolio	0.0145	pure
CY2021Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	597463000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	592743000	USD
CY2021	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	0	USD
CY2021Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	3453459000	USD
CY2021Q4	mbwm	Loan Portfolio Classes And Segments As Percentage Of Aggregate Loan LoanPortfolioClassesAndSegmentsAsPercentageOfAggregateLoan	1.000	pure
CY2020Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	3193470000	USD
CY2020Q4	mbwm	Loan Portfolio Classes And Segments As Percentage Of Aggregate Loan LoanPortfolioClassesAndSegmentsAsPercentageOfAggregateLoan	1.000	pure
CY2021	mbwm	Loans And Leases Receivable Net Of Deferred Income Increase Decrease Percentage LoansAndLeasesReceivableNetOfDeferredIncomeIncreaseDecreasePercentage	0.081	pure
CY2021Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	3453459000	USD
CY2021Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	155000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	3193470000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	0	USD
CY2021Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance	16997000	USD
CY2021Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment	15715000	USD
CY2021	us-gaap	Impaired Financing Receivable With No Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment	19857000	USD
CY2021Q4	us-gaap	Impaired Financing Receivable With Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance	3671000	USD
CY2021Q4	us-gaap	Impaired Financing Receivable With Related Allowance Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment	3651000	USD
CY2021Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	546000	USD
CY2021	us-gaap	Impaired Financing Receivable With Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment	3440000	USD
CY2021Q4	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	20668000	USD
CY2021Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	19366000	USD
CY2021Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	546000	USD
CY2021	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	23297000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance	26892000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment	24738000	USD
CY2020	us-gaap	Impaired Financing Receivable With No Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment	17315000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable With Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance	2266000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable With Related Allowance Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment	2220000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	551000	USD
CY2020	us-gaap	Impaired Financing Receivable With Related Allowance Average Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment	2742000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable Unpaid Principal Balance ImpairedFinancingReceivableUnpaidPrincipalBalance	29158000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	26958000	USD
CY2020Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	551000	USD
CY2020	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	20057000	USD
CY2021	us-gaap	Impaired Financing Receivable Interest Income Accrual Method ImpairedFinancingReceivableInterestIncomeAccrualMethod	1500000	USD
CY2020	us-gaap	Impaired Financing Receivable Interest Income Accrual Method ImpairedFinancingReceivableInterestIncomeAccrualMethod	1300000	USD
CY2020	mbwm	Loans And Leases Receivable Nonaccrual Loans Interest Income Recognized LoansAndLeasesReceivableNonaccrualLoansInterestIncomeRecognized	100000	USD
CY2021	us-gaap	Loans And Leases Receivable Impaired Interest Lost On Nonaccrual Loans LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans	100000	USD
CY2020	us-gaap	Loans And Leases Receivable Impaired Interest Lost On Nonaccrual Loans LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans	200000	USD
CY2019	us-gaap	Loans And Leases Receivable Impaired Interest Lost On Nonaccrual Loans LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans	100000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	37967000	USD
CY2021	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-4300000	USD
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	1044000	USD
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	2740000	USD
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	35363000	USD
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	546000	USD
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	34817000	USD
CY2021Q4	mbwm	Loans And Leases Receivable Net Of Deferred Income Excluding Ppp Loans LoansAndLeasesReceivableNetOfDeferredIncomeExcludingPPPLoans	3413349000	USD
CY2021Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	19366000	USD
CY2021Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	3393983000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	23889000	USD
CY2020	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	14050000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	838000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	866000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	37967000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	551000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	37416000	USD
CY2020Q4	mbwm	Loans And Leases Receivable Net Of Deferred Income Excluding Ppp Loans LoansAndLeasesReceivableNetOfDeferredIncomeExcludingPPPLoans	2828211000	USD
CY2020Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	26958000	USD
CY2020Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	2801253000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	22380000	USD
CY2019	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1750000	USD
CY2020	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	22498000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	94169000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	23889000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	1623000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	22266000	USD
CY2019Q4	mbwm	Loans And Leases Receivable Net Of Deferred Income Excluding Ppp Loans LoansAndLeasesReceivableNetOfDeferredIncomeExcludingPPPLoans	2856667000	USD
CY2019Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	14622000	USD
CY2019Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	2842045000	USD
CY2021	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	18	pure
CY2021	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	4333000	USD
CY2021	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	4329000	USD
CY2020	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	45	pure
CY2019	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	883000	USD
CY2019	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	642000	USD
CY2020	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	23298000	USD
CY2021	mbwm	Minimum Number Of Days Past Due At Period End For Loans Modified As Troubled Debt Restructurings MinimumNumberOfDaysPastDueAtPeriodEndForLoansModifiedAsTroubledDebtRestructurings	P30D
CY2021	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	pure
CY2021	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	0	USD
CY2020	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	pure
CY2020	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	0	USD
CY2021Q4	mbwm	Allowance For Credit Losses Troubled Debt Restructuring AllowanceForCreditLossesTroubledDebtRestructuring	519000	USD
CY2020Q4	mbwm	Allowance For Credit Losses Troubled Debt Restructuring AllowanceForCreditLossesTroubledDebtRestructuring	467000	USD
CY2021Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	36955000	USD
CY2020Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	35210000	USD
CY2021Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	57298000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	600000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	58959000	USD
CY2021	us-gaap	Depreciation Depreciation	5800000	USD
CY2020	us-gaap	Depreciation Depreciation	5200000	USD
CY2019	us-gaap	Depreciation Depreciation	3900000	USD
CY2021Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P2Y9M18D
CY2021Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0471	pure
CY2021	us-gaap	Operating Lease Expense OperatingLeaseExpense	600000	USD
CY2019	us-gaap	Operating Lease Expense OperatingLeaseExpense	500000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	3600000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	800000	USD
CY2021Q4	mbwm	Lessee Operating Lease Liability To Be Paid Year Two And Year Three LesseeOperatingLeaseLiabilityToBePaidYearTwoAndYearThree	1400000	USD
CY2021Q4	mbwm	Lessee Operating Lease Liability To Be Paid Year Four And Year Five LesseeOperatingLeaseLiabilityToBePaidYearFourAndYearFive	300000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	1100000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	3400000	USD
CY2020Q4	mbwm	Lessee Operating Lease Liability To Be Paid Year Two And Year Three LesseeOperatingLeaseLiabilityToBePaidYearTwoAndYearThree	1200000	USD
CY2020Q4	mbwm	Lessee Operating Lease Liability To Be Paid Year Four And Year Five LesseeOperatingLeaseLiabilityToBePaidYearFourAndYearFive	500000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	1100000	USD
CY2021Q4	us-gaap	Continuing Involvement With Transferred Financial Assets Principal Amount Outstanding ContinuingInvolvementWithTransferredFinancialAssetsPrincipalAmountOutstanding	1344055000	USD
CY2020Q4	us-gaap	Continuing Involvement With Transferred Financial Assets Principal Amount Outstanding ContinuingInvolvementWithTransferredFinancialAssetsPrincipalAmountOutstanding	1038928000	USD
CY2021Q4	mbwm	Continuing Involvement With Transferred Financial Assets Custodial Escrow Balance ContinuingInvolvementWithTransferredFinancialAssetsCustodialEscrowBalance	12100000	USD
CY2020Q4	mbwm	Continuing Involvement With Transferred Financial Assets Custodial Escrow Balance ContinuingInvolvementWithTransferredFinancialAssetsCustodialEscrowBalance	11800000	USD
CY2020Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	8189000	USD
CY2019Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	4652000	USD
CY2021	us-gaap	Servicing Asset At Amortized Value Additions ServicingAssetAtAmortizedValueAdditions	7711000	USD
CY2020	us-gaap	Servicing Asset At Amortized Value Additions ServicingAssetAtAmortizedValueAdditions	6467000	USD
CY2021	us-gaap	Servicing Asset At Amortized Value Amortization1 ServicingAssetAtAmortizedValueAmortization1	3652000	USD
CY2020	us-gaap	Servicing Asset At Amortized Value Amortization1 ServicingAssetAtAmortizedValueAmortization1	2930000	USD
CY2021Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	12248000	USD
CY2020Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	8189000	USD
CY2021Q4	us-gaap	Valuation Allowance For Impairment Of Recognized Servicing Assets Balance ValuationAllowanceForImpairmentOfRecognizedServicingAssetsBalance	0	USD
CY2021Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	15400000	USD
CY2020Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	10000000.0	USD
CY2021	us-gaap	Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Discount Rate ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueDiscountRate	0.080	pure
CY2021	us-gaap	Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Prepayment Speed ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValuePrepaymentSpeed	0.074	pure
CY2021	us-gaap	Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Expected Credit Losses ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueExpectedCreditLosses	0.0025	pure
CY2020	us-gaap	Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Discount Rate ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueDiscountRate	0.0775	pure
CY2020	us-gaap	Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Prepayment Speed ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValuePrepaymentSpeed	0.140	pure
CY2020	us-gaap	Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Expected Credit Losses ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueExpectedCreditLosses	0.0040	pure
CY2021	us-gaap	Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Weighted Average Life1 ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueWeightedAverageLife1	P8Y6M
CY2020	us-gaap	Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Weighted Average Life1 ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueWeightedAverageLife1	P6Y1M6D
CY2021Q4	mbwm	Mortgage Servicing Rights Amortization Expense Next Twelve Months MortgageServicingRightsAmortizationExpenseNextTwelveMonths	1186000	USD
CY2021Q4	mbwm	Mortgage Servicing Rights Amortization Expense Year Two MortgageServicingRightsAmortizationExpenseYearTwo	992000	USD
CY2021Q4	mbwm	Mortgage Servicing Rights Amortization Expense Year Three MortgageServicingRightsAmortizationExpenseYearThree	814000	USD
CY2021Q4	mbwm	Mortgage Servicing Rights Amortization Expense Year Four MortgageServicingRightsAmortizationExpenseYearFour	654000	USD
CY2021Q4	mbwm	Mortgage Servicing Rights Amortization Expense Year Five MortgageServicingRightsAmortizationExpenseYearFive	516000	USD
CY2021Q4	mbwm	Mortgage Servicing Rights Amortization Expense After Year Five MortgageServicingRightsAmortizationExpenseAfterYearFive	8086000	USD
CY2021Q4	us-gaap	Finite Lived Core Deposits Gross FiniteLivedCoreDepositsGross	17500000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	16100000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	1400000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	15100000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	2400000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	768000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	450000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	133000	USD
CY2021Q4	us-gaap	Noninterest Bearing Domestic Deposit Demand NoninterestBearingDomesticDepositDemand	1677952000	USD
CY2021Q4	mbwm	Percentage Of Non Interest Bearing Domestic Deposits To Deposits Demand PercentageOfNonInterestBearingDomesticDepositsToDepositsDemand	0.411	pure
CY2020Q4	us-gaap	Noninterest Bearing Domestic Deposit Demand NoninterestBearingDomesticDepositDemand	1433403000	USD
CY2020Q4	mbwm	Percentage Of Non Interest Bearing Domestic Deposits To Deposits Demand PercentageOfNonInterestBearingDomesticDepositsToDepositsDemand	0.420	pure
CY2021	mbwm	Percentage Of Increase Decrease In Non Interest Bearing Demand Deposits PercentageOfIncreaseDecreaseInNonInterestBearingDemandDeposits	0.171	pure
CY2021Q4	us-gaap	Interest Bearing Domestic Deposit Checking InterestBearingDomesticDepositChecking	538838000	USD
CY2021Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Checking PercentageOfInterestBearingDomesticDepositsToDepositsChecking	0.132	pure
CY2020Q4	us-gaap	Interest Bearing Domestic Deposit Checking InterestBearingDomesticDepositChecking	473053000	USD
CY2020Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Checking PercentageOfInterestBearingDomesticDepositsToDepositsChecking	0.139	pure
CY2021	mbwm	Percentage Of Increase Decrease Of Interest Bearing Checking Deposits PercentageOfIncreaseDecreaseOfInterestBearingCheckingDeposits	0.139	pure
CY2021Q4	us-gaap	Interest Bearing Domestic Deposit Money Market InterestBearingDomesticDepositMoneyMarket	1040176000	USD
CY2021Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Money Market PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket	0.255	pure
CY2020Q4	us-gaap	Interest Bearing Domestic Deposit Money Market InterestBearingDomesticDepositMoneyMarket	611912000	USD
CY2020Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Money Market PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket	0.179	pure
CY2021	mbwm	Percentage Of Increase Decrease In Money Market Deposits PercentageOfIncreaseDecreaseInMoneyMarketDeposits	0.700	pure
CY2021Q4	us-gaap	Interest Bearing Domestic Deposit Savings InterestBearingDomesticDepositSavings	394330000	USD
CY2021Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Savings PercentageOfInterestBearingDomesticDepositsToDepositsSavings	0.097	pure
CY2020Q4	us-gaap	Interest Bearing Domestic Deposit Savings InterestBearingDomesticDepositSavings	338070000	USD
CY2020Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Savings PercentageOfInterestBearingDomesticDepositsToDepositsSavings	0.099	pure
CY2021	mbwm	Percentage Of Increase Or Decrease Of Savings Deposits PercentageOfIncreaseOrDecreaseOfSavingsDeposits	0.166	pure
CY2021Q4	mbwm	Domestic Time Deposits Less Than100000 DomesticTimeDepositsLessThan100000	132776000	USD
CY2021Q4	mbwm	Percentage Of Domestic Time Deposits Under100000 PercentageOfDomesticTimeDepositsUnder100000	0.032	pure
CY2020Q4	mbwm	Domestic Time Deposits Less Than100000 DomesticTimeDepositsLessThan100000	165548000	USD
CY2020Q4	mbwm	Percentage Of Domestic Time Deposits Under100000 PercentageOfDomesticTimeDepositsUnder100000	0.049	pure
CY2021	mbwm	Percentage Of Increase Decrease In Domestic Time Deposits Under100000 PercentageOfIncreaseDecreaseInDomesticTimeDepositsUnder100000	-0.198	pure
CY2021Q4	mbwm	Domestic Time Deposits100000 Or More DomesticTimeDeposits100000OrMore	275208000	USD
CY2021Q4	mbwm	Percentage Of Domestic Time Deposits100000 And Over PercentageOfDomesticTimeDeposits100000AndOver	0.067	pure
CY2020Q4	mbwm	Domestic Time Deposits100000 Or More DomesticTimeDeposits100000OrMore	342633000	USD
CY2020Q4	mbwm	Percentage Of Domestic Time Deposits100000 And Over PercentageOfDomesticTimeDeposits100000AndOver	0.100	pure
CY2021	mbwm	Percentage Of Increase Decrease In Domestic Time Deposits100000 And Over PercentageOfIncreaseDecreaseInDomesticTimeDeposits100000AndOver	-0.197	pure
CY2021Q4	mbwm	Aggregate Local Deposit Liabilities AggregateLocalDepositLiabilities	4059280000	USD
CY2021Q4	mbwm	Aggregate Percentage Of Local Deposits AggregatePercentageOfLocalDeposits	0.994	pure
CY2020Q4	mbwm	Aggregate Local Deposit Liabilities AggregateLocalDepositLiabilities	3364619000	USD
CY2020Q4	mbwm	Aggregate Percentage Of Local Deposits AggregatePercentageOfLocalDeposits	0.986	pure
CY2021	mbwm	Aggregate Percentage Increase Decrease In Local Deposits AggregatePercentageIncreaseDecreaseInLocalDeposits	0.206	pure
CY2021Q4	mbwm	Out Of Area Time Deposits100000 And Over OutOfAreaTimeDeposits100000AndOver	23913000	USD
CY2021Q4	mbwm	Percentage Of Out Of Area Time Deposits100000 And Over PercentageOfOutOfAreaTimeDeposits100000AndOver	0.006	pure
CY2020Q4	mbwm	Out Of Area Time Deposits100000 And Over OutOfAreaTimeDeposits100000AndOver	46934000	USD
CY2020Q4	mbwm	Percentage Of Out Of Area Time Deposits100000 And Over PercentageOfOutOfAreaTimeDeposits100000AndOver	0.014	pure
CY2021	mbwm	Percentage Of Increase Decrease In Out Of Area Time100000 And Over PercentageOfIncreaseDecreaseInOutOfAreaTime100000AndOver	-0.490	pure
CY2021Q4	us-gaap	Deposits Deposits	4083193000	USD
CY2021Q4	mbwm	Aggregate Percentage Of Deposits AggregatePercentageOfDeposits	1.000	pure
CY2020Q4	us-gaap	Deposits Deposits	3411553000	USD
CY2020Q4	mbwm	Aggregate Percentage Of Deposits AggregatePercentageOfDeposits	1.000	pure
CY2021	mbwm	Aggregate Increase Decrease In Percentage Of Deposits AggregateIncreaseDecreaseInPercentageOfDeposits	0.197	pure
CY2021Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	260501000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	327246000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	78024000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	139801000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	34595000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	39801000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	7863000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	25577000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	50914000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	22690000	USD
CY2021Q4	us-gaap	Time Deposits TimeDeposits	431897000	USD
CY2020Q4	us-gaap	Time Deposits TimeDeposits	555115000	USD
CY2021Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More Three Months Or Less ContractualMaturitiesTimeDeposits100000OrMoreThreeMonthsOrLess	68887000	USD
CY2020Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More Three Months Or Less ContractualMaturitiesTimeDeposits100000OrMoreThreeMonthsOrLess	79500000	USD
CY2021Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More Three Months Through Six Months ContractualMaturitiesTimeDeposits100000OrMoreThreeMonthsThroughSixMonths	53077000	USD
CY2020Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More Three Months Through Six Months ContractualMaturitiesTimeDeposits100000OrMoreThreeMonthsThroughSixMonths	79373000	USD
CY2021Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More Six Months Through12 Months ContractualMaturitiesTimeDeposits100000OrMoreSixMonthsThrough12Months	56612000	USD
CY2020Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More Six Months Through12 Months ContractualMaturitiesTimeDeposits100000OrMoreSixMonthsThrough12Months	77363000	USD
CY2021Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More After12 Months ContractualMaturitiesTimeDeposits100000OrMoreAfter12Months	120545000	USD
CY2020Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More After12 Months ContractualMaturitiesTimeDeposits100000OrMoreAfter12Months	153331000	USD
CY2021Q4	us-gaap	Time Deposits100000 Or More TimeDeposits100000OrMore	299121000	USD
CY2020Q4	us-gaap	Time Deposits100000 Or More TimeDeposits100000OrMore	389567000	USD
CY2021Q4	us-gaap	Time Deposits At Or Above Fdic Insurance Limit TimeDepositsAtOrAboveFDICInsuranceLimit	207000000	USD
CY2020Q4	us-gaap	Time Deposits At Or Above Fdic Insurance Limit TimeDepositsAtOrAboveFDICInsuranceLimit	272000000	USD
CY2021	us-gaap	Schedule Of Repurchase Agreements ScheduleOfRepurchaseAgreements	<table cellpadding="0" cellspacing="0" class="finTable" style="width: 95%; font-size: 10pt; font-family: "Times New Roman", Times, serif; text-indent: 0px; margin-left: 9pt; margin-right: auto;"> <tbody> <tr style="vertical-align: bottom; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; text-align: center; margin: 0pt;">2021</p> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 1px;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; text-align: center; margin: 0pt;">2020</p> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 1px;"> </td> </tr> <tr style="vertical-align: bottom; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204, 238, 255); font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; width: 70%;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin-top: 0pt; margin-bottom: 0pt;">Outstanding balance at year-end</p> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">$</td> <td style="width: 12%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">197,463,000</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">$</td> <td style="width: 12%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">118,365,000</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(255, 255, 255); font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin-top: 0pt; margin-bottom: 0pt;">Weighted average interest rate at year-end</p> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 12%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">0.11</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin: 0pt;">%</p> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 12%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">0.12</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin: 0pt;">%</p> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204, 238, 255); font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(255, 255, 255); font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin-top: 0pt; margin-bottom: 0pt;">Average daily balance during the year</p> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">$</td> <td style="width: 12%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">158,855,000</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">$</td> <td style="width: 12%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">132,880,000</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204, 238, 255); font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin-top: 0pt; margin-bottom: 0pt;">Weighted average interest rate during the year</p> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 12%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">0.11</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin: 0pt;">%</p> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 12%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">0.12</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin: 0pt;">%</p> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(255, 255, 255); font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204, 238, 255); font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin-top: 0pt; margin-bottom: 0pt;">Maximum daily balance during the year</p> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">$</td> <td style="width: 12%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">209,093,000</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">$</td> <td style="width: 12%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">173,186,000</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> </tr> </tbody> </table>
CY2021Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	197463000	USD
CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	118365000	USD
CY2021	us-gaap	Shortterm Debt Average Outstanding Amount ShorttermDebtAverageOutstandingAmount	158855000	USD
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CY2021	us-gaap	Shortterm Debt Maximum Amount Outstanding During Period ShorttermDebtMaximumAmountOutstandingDuringPeriod	209093000	USD
CY2020	us-gaap	Shortterm Debt Maximum Amount Outstanding During Period ShorttermDebtMaximumAmountOutstandingDuringPeriod	173186000	USD
CY2021Q4	us-gaap	Line Of Credit Facility Maximum Borrowing Capacity LineOfCreditFacilityMaximumBorrowingCapacity	889000000	USD
CY2021Q4	us-gaap	Line Of Credit Facility Remaining Borrowing Capacity LineOfCreditFacilityRemainingBorrowingCapacity	509000000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	94000000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due From One To Two Years Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromOneToTwoYearsOfBalanceSheetDate	80000000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due From Two To Three Years Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromTwoToThreeYearsOfBalanceSheetDate	80000000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due From Three To Four Years Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromThreeToFourYearsOfBalanceSheetDate	50000000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due From Four To Five Years Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromFourToFiveYearsOfBalanceSheetDate	30000000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due After Five Years Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueAfterFiveYearsOfBalanceSheetDate	40000000	USD
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	12675000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	14945000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	10978000	USD
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2020000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-4141000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	26000	USD
CY2021	mbwm	Income Tax Expense Benefit Continuing Operations Change In Valuation Allowance IncomeTaxExpenseBenefitContinuingOperationsChangeInValuationAllowance	0	USD
CY2020	mbwm	Income Tax Expense Benefit Continuing Operations Change In Valuation Allowance IncomeTaxExpenseBenefitContinuingOperationsChangeInValuationAllowance	-94000	USD
CY2019	mbwm	Income Tax Expense Benefit Continuing Operations Change In Valuation Allowance IncomeTaxExpenseBenefitContinuingOperationsChangeInValuationAllowance	0	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14695000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	10710000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	11004000	USD
CY2021	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	15481000	USD
CY2020	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	11518000	USD
CY2019	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	12697000	USD
CY2021	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	658000	USD
CY2020	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	681000	USD
CY2019	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	644000	USD
CY2021	mbwm	Effective Income Tax Reconciliation Bank Owned Life Insurance EffectiveIncomeTaxReconciliationBankOwnedLifeInsurance	233000	USD
CY2020	mbwm	Effective Income Tax Reconciliation Bank Owned Life Insurance EffectiveIncomeTaxReconciliationBankOwnedLifeInsurance	238000	USD
CY2019	mbwm	Effective Income Tax Reconciliation Bank Owned Life Insurance EffectiveIncomeTaxReconciliationBankOwnedLifeInsurance	804000	USD
CY2021	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	0	USD
CY2020	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	-94000	USD
CY2019	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	0	USD
CY2021	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	105000	USD
CY2020	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	205000	USD
CY2019	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-245000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14695000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	10710000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	11004000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21	pure
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	7426000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	7973000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	259000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	511000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	941000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	541000	USD
CY2021Q4	mbwm	Deferred Tax Assets Non Accrual Loan Interest Income DeferredTaxAssetsNonAccrualLoanInterestIncome	159000	USD
CY2020Q4	mbwm	Deferred Tax Assets Non Accrual Loan Interest Income DeferredTaxAssetsNonAccrualLoanInterestIncome	211000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Deferred Income DeferredTaxAssetsDeferredIncome	520000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Deferred Income DeferredTaxAssetsDeferredIncome	924000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	991000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	0	USD
CY2021Q4	mbwm	Deferred Tax Assets Fair Value Write Downs On Foreclosed Properties DeferredTaxAssetsFairValueWriteDownsOnForeclosedProperties	0	USD
CY2020Q4	mbwm	Deferred Tax Assets Fair Value Write Downs On Foreclosed Properties DeferredTaxAssetsFairValueWriteDownsOnForeclosedProperties	537000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	1344000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	938000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	11640000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	11635000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	1168000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	1175000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	416000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	297000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	276000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	498000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Mortgage Servicing Rights DeferredTaxLiabilitiesMortgageServicingRights	2572000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Mortgage Servicing Rights DeferredTaxLiabilitiesMortgageServicingRights	1720000	USD
CY2021Q4	mbwm	Deferred Tax Liabilities Unrealized Gains On Available For Sale Securities DeferredTaxLiabilitiesUnrealizedGainsOnAvailableForSaleSecurities	0	USD
CY2020Q4	mbwm	Deferred Tax Liabilities Unrealized Gains On Available For Sale Securities DeferredTaxLiabilitiesUnrealizedGainsOnAvailableForSaleSecurities	1458000	USD
CY2021Q4	mbwm	Deferred Tax Liabilities Business Combination Adjustments DeferredTaxLiabilitiesBusinessCombinationAdjustments	2013000	USD
CY2020Q4	mbwm	Deferred Tax Liabilities Business Combination Adjustments DeferredTaxLiabilitiesBusinessCombinationAdjustments	2142000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	942000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	521000	USD
CY2021Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	7387000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	7811000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	4253000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	3824000	USD
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized	187000
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0
CY2020	us-gaap	Net Income Loss NetIncomeLoss	44138000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	49456000	USD
CY2021Q4	mbwm	Related Party Deposits And Repurchase Agreements RelatedPartyDepositsAndRepurchaseAgreements	18400000	USD
CY2020Q4	mbwm	Related Party Deposits And Repurchase Agreements RelatedPartyDepositsAndRepurchaseAgreements	19400000	USD
CY2021Q4	mbwm	Reserve Or Liability Balance For Financial Instruments With Off Balance Sheet Risk ReserveOrLiabilityBalanceForFinancialInstrumentsWithOffBalanceSheetRisk	0	USD
CY2021Q4	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Amount Liability FairValueDisclosureOffbalanceSheetRisksAmountLiability	1565871000	USD
CY2020Q4	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Amount Liability FairValueDisclosureOffbalanceSheetRisksAmountLiability	1430195000	USD
CY2014	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent DefinedContributionPlanEmployerMatchingContributionPercent	0.0425	pure
	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent DefinedContributionPlanEmployerMatchingContributionPercent	0.0500	pure
CY2021	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	2100000	USD
CY2020	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	1900000	USD
CY2019	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	1700000	USD
CY2021	mbwm	Interest Expense Deferred Compensation Plan InterestExpenseDeferredCompensationPlan	100000	USD
CY2020	mbwm	Interest Expense Deferred Compensation Plan InterestExpenseDeferredCompensationPlan	100000	USD
CY2021Q4	us-gaap	Mortgages Held For Sale Fair Value Disclosure MortgagesHeldForSaleFairValueDisclosure	16700000	USD
CY2020Q4	us-gaap	Mortgages Held For Sale Fair Value Disclosure MortgagesHeldForSaleFairValueDisclosure	24000000.0	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	59021000	USD
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	15986857
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	16268689
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	16405159
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.69
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.71
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.01
CY2021	us-gaap	Net Income Loss NetIncomeLoss	59021000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	44138000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	49456000	USD
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	15986857
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	16268689
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	16405159
CY2021	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	446
CY2020	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	630
CY2019	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	3976
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	15987303
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	16269319
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	16409135
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.69
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.71
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.01
CY2014Q2	mbwm	Fair Value Discount Of Subordinated Debentures Related To Assumed Business Trusts At Time Af Merger FairValueDiscountOfSubordinatedDebenturesRelatedToAssumedBusinessTrustsAtTimeAfMerger	15000000.0	USD
CY2014Q2	mbwm	Amortization Of Fair Value Discount Related To Subordinated Debentures Of Assumed Business Trusts AmortizationOfFairValueDiscountRelatedToSubordinatedDebenturesOfAssumedBusinessTrusts	700000	USD
CY2014Q2	mbwm	Amortization Period Of Fair Value Discount Related To Subordinated Debentures Of Assumed Business Trusts AmortizationPeriodOfFairValueDiscountRelatedToSubordinatedDebenturesOfAssumedBusinessTrusts	P21Y6M
CY2021Q4	mbwm	Capital Conservation Buffer CapitalConservationBuffer	0.025	pure
CY2021Q4	mbwm	Common Equity Tier1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets CommonEquityTier1RiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.070	pure
CY2021Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.085	pure
CY2021Q4	us-gaap	Capital Required For Capital Adequacy To Risk Weighted Assets CapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.105	pure
CY2021Q4	us-gaap	Statutory Accounting Practices Statutory Amount Available For Dividend Payments Without Regulatory Approval StatutoryAccountingPracticesStatutoryAmountAvailableForDividendPaymentsWithoutRegulatoryApproval	108000000	USD
CY2021Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.29
CY2021Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.29
CY2021Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.30
CY2019Q2	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	20000000.0	USD
CY2021	us-gaap	Stock Repurchased During Period Shares StockRepurchasedDuringPeriodShares	683000
CY2021	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	21400000	USD
CY2021	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	31.29
CY2021Q4	us-gaap	Stock Repurchase Program Remaining Authorized Repurchase Amount1 StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1	6800000	USD
CY2021Q4	mbwm	Preferred Securities Of Subsidiary Trust PreferredSecuritiesOfSubsidiaryTrust	46200000	USD
CY2020Q4	mbwm	Preferred Securities Of Subsidiary Trust PreferredSecuritiesOfSubsidiaryTrust	45500000	USD
CY2021	mbwm	Maximum Restricted Core Element Allowed In Tier One Capital Percent MaximumRestrictedCoreElementAllowedInTierOneCapitalPercent	0.25	pure
CY2009Q4	mbwm	Maximum Level Of Consolidated Aggregate Assets Allowing For Inclusion Of Trust Preferred Securities In Tier One Capital MaximumLevelOfConsolidatedAggregateAssetsAllowingForInclusionOfTrustPreferredSecuritiesInTierOneCapital	15000000000.0	USD
CY2021Q4	mbwm	Trust Preferred Securities Included In Tier One Capital TrustPreferredSecuritiesIncludedInTierOneCapital	46200000	USD
CY2020Q4	mbwm	Trust Preferred Securities Included In Tier One Capital TrustPreferredSecuritiesIncludedInTierOneCapital	45500000	USD
CY2021Q4	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-3700000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	5500000	USD
CY2021Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	34786000	USD
CY2021Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	29533000	USD
CY2021Q1	us-gaap	Net Income Loss NetIncomeLoss	14240000	USD
CY2021Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.87
CY2021Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.87
CY2021Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	35774000	USD
CY2021Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	30871000	USD
CY2021Q2	us-gaap	Net Income Loss NetIncomeLoss	18091000	USD
CY2021Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.12
CY2021Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.12
CY2021Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	35888000	USD
CY2021Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	31124000	USD
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	15051000	USD
CY2021Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.95
CY2021Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.95
CY2021Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	37046000	USD
CY2021Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	32534000	USD
CY2021Q4	us-gaap	Net Income Loss NetIncomeLoss	11639000	USD
CY2021Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.74
CY2021Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.74
CY2020Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	37935000	USD
CY2020Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	30317000	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	10673000	USD
CY2020Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.65
CY2020Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.65
CY2020Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	37164000	USD
CY2020Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	30571000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	8697000	USD
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.54
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.54
CY2020Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	35594000	USD
CY2020Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	29509000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	10686000	USD
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.66
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.66
CY2020Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	37620000	USD
CY2020Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	31849000	USD
CY2020Q4	us-gaap	Net Income Loss NetIncomeLoss	14082000	USD
CY2020Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.86
CY2020Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.86

Files In Submission

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0001437749-22-005284-index-headers.html	Edgar Link	pending
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0001437749-22-005284.txt	Edgar Link	pending
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$MBWM
Mercantile Bank Corp Stock $mbwm

2021 Q4 Form 10-K Financial Statement

#000143774922005284 Filed on March 04, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$MBWM Mercantile Bank Corp Stock $mbwm

2021 Q4 Form 10-K Financial Statement

#000143774922005284 Filed on March 04, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$MBWM
Mercantile Bank Corp Stock $mbwm