XML 97 R83.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Note 8 - Deposits - Summary of Deposits (Details) - USD ($) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2019 | Dec. 31, 2018
Noninterest-bearing | $ 924,916,000 | $ 889,784,000
Noninterest-bearing demand, percentage | 34.40% | 36.10%
Noninterest-bearing demand, percent increase | 3.90% |
Interest-bearing checking | $ 332,373,000 | $ 339,089,000
Interest-bearing checking, percentage | 12.30% | 13.80%
Interest-bearing checking, percent increase (decrease) | (2.00%) |
Money market | $ 509,368,000 | $ 434,333,000
Money market, percentage | 18.90% | 17.60%
Money market, percent increase (decrease) | 17.30% |
Savings | $ 269,318,000 | $ 317,014,000
Savings, percentage | 10.00% | 12.90%
Savings, percent increase (decrease) | (15.00%) |
Local Time, under $100,000 | $ 198,123,000 | $ 160,092,000
Local Time, under $100,000, percentage | 7.40% | 6.50%
Local Time, under $100,000, percent increase (decrease) | 23.80% |
Local Time, $100,000 and over | $ 322,827,000 | $ 210,164,000
Local Time, $100,000 and over, percentage | 12.00% | 8.50%
Local Time, $100,000 and over, percent increase (decrease) | 53.60% |
Total local deposits | $ 2,556,925,000 | $ 2,350,476,000
Total local deposits, percentage | 95.00% | 95.40%
Total local deposits, percent increase (decrease) | 8.80% |
Out-of-area time, under $100,000 | $ 0 | $ 0
Out-of-area time, under $100,000, percentage | 0.00% | 0.00%
Out-of-area time, under $100,000, percent increase (decrease) | 0.00% |
Out-of-area time, $100,000 and over | $ 133,459,000 | $ 113,232,000
Out-of-area time, $100,000 and over, percentage | 5.00% | 4.60%
Out-of-area time, $100,000 and over, percent increase (decrease) | 17.90% |
Total out-of-area deposits | $ 133,459,000 | $ 113,232,000
Total out-of-area deposits, percentage | 5.00% | 4.60%
Total out-of-area deposits, percent increase (decrease) | 17.90% |
Total deposits | $ 2,690,384,000 | $ 2,463,708,000
Total deposits, percentage | 100.00% | 100.00%
Total deposits, percent increase (decrease) | 9.20% |

X
- Definition The percentage of increase or (decrease) during the period in deposit liabilities. + References No definition available. + Details
Name: | mbwm_AggregateIncreaseDecreaseInPercentageOfDeposits
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value of liabilities related to local deposits. + References No definition available. + Details
Name: | mbwm_AggregateLocalDepositLiabilities
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Value of liabilities related to out-of-area time deposits. + References No definition available. + Details
Name: | mbwm_AggregateOutOfAreaTimeDeposits
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The percentage of increase or (decrease) during the period in domestic deposit liabilities. + References No definition available. + Details
Name: | mbwm_AggregatePercentageIncreaseDecreaseInLocalDeposits
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage of increase or (decrease) during the period in out-of-area deposit liabilities. + References No definition available. + Details
Name: | mbwm_AggregatePercentageIncreaseDecreaseInOutOfAreaDeposits
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents a percentage of total deposits. + References No definition available. + Details
Name: | mbwm_AggregatePercentageOfDeposits
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents a percentage of domestic deposit liabilities. + References No definition available. + Details
Name: | mbwm_AggregatePercentageOfLocalDeposits
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents a percentage of out-of-area deposits + References No definition available. + Details
Name: | mbwm_AggregatePercentageOfOutOfAreaDeposits
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of local time deposit liabilities, including certificates of deposit, in denominations of $100,000 or more. + References No definition available. + Details
Name: | mbwm_DomesticTimeDeposits100000OrMore
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of domestic time deposit liabilities, including certificates of deposit, in denominations of less than $100,000. + References No definition available. + Details
Name: | mbwm_DomesticTimeDepositsLessThan100000
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The aggregate amount of out-of-area time deposits (including certificates of deposits, individual retirement accounts and open accounts) in denominations of $100,000 or more. + References No definition available. + Details
Name: | mbwm_OutOfAreaTimeDeposits100000AndOver
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The aggregate amount of out-of-area time deposits (including certificates of deposits, individual retirement accounts and open accounts) that total to less than $100,000. + References No definition available. + Details
Name: | mbwm_OutOfAreaTimeDepositsUnder100000
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The percentage of domestic time deposit liabilities (including certificates of deposits, individual retirement accounts and open accounts) in denominations of $100,000 or more. + References No definition available. + Details
Name: | mbwm_PercentageOfDomesticTimeDeposits100000AndOver
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The percentage of domestic time deposits (including certificates of deposits, individual retirement accounts and open accounts) that total to less than $100,000. + References No definition available. + Details
Name: | mbwm_PercentageOfDomesticTimeDepositsUnder100000
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of increase or (decrease) in domestic time deposit liabilities (including certificates of deposits, individual retirement accounts and open accounts) in denominations of $100,000 or more + References No definition available. + Details
Name: | mbwm_PercentageOfIncreaseDecreaseInDomesticTimeDeposits100000AndOver
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of increase or (decrease) in domestic time deposits (including certificates of deposits, individual retirement accounts and open accounts) that total to less than $100,000. + References No definition available. + Details
Name: | mbwm_PercentageOfIncreaseDecreaseInDomesticTimeDepositsUnder100000
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of increase or (decrease) in interest-bearing domestic money market demand account deposit liabilities. + References No definition available. + Details
Name: | mbwm_PercentageOfIncreaseDecreaseInMoneyMarketDeposits
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of increase or (decrease) in noninterest-bearing domestic accounts that entitle the depositor to withdraw funds at any time without prior notice, also known as demand deposits. + References No definition available. + Details
Name: | mbwm_PercentageOfIncreaseDecreaseInNonInterestBearingDemandDeposits
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of increase or (decrease) in out-of-area time deposit liabilities (including certificates of deposits, individual retirement accounts and open accounts) in denominations of $100,000 or more. + References No definition available. + Details
Name: | mbwm_PercentageOfIncreaseDecreaseInOutOfAreaTime100000AndOver
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of increase or (decrease) in out-of-area time deposits (including certificates of deposits, individual retirement accounts and open accounts) that total to less than $100,000. + References No definition available. + Details
Name: | mbwm_PercentageOfIncreaseDecreaseInOutOfAreaTimeUnder100000
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of increase or (decrease) in interest-bearing domestic checking deposit liabilities. + References No definition available. + Details
Name: | mbwm_PercentageOfIncreaseDecreaseOfInterestBearingCheckingDeposits
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of increase or (decrease) in interest-bearing domestic savings deposit liabilities. Saving deposits bear interest and have no stated maturity. + References No definition available. + Details
Name: | mbwm_PercentageOfIncreaseOrDecreaseOfSavingsDeposits
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of money in noninterest-bearing domestic accounts that entitle the depositor to withdraw funds at any time without prior notice, also known as demand deposits. + References No definition available. + Details
Name: | mbwm_PercentageOfNonInterestBearingDomesticDepositsToDepositsDemand
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The percentage of out-of-area time deposits (including certificates of deposits, individual retirement accounts and open accounts) that total to less than $100,000. + References No definition available. + Details
Name: | mbwm_PercentageOfOutOfAreaTimeDepositUnder100000
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The percentage of out-of-area time deposit liabilities (including certificates of deposits, individual retirement accounts and open accounts) in denominations of $100,000 or more. + References No definition available. + Details
Name: | mbwm_PercentageOfOutOfAreaTimeDeposits100000AndOver
Namespace Prefix: | mbwm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.12) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_Deposits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of interest-bearing domestic checking deposit liabilities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.12) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_InterestBearingDomesticDepositChecking
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of interest-bearing domestic money market demand account deposit liabilities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.12) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_InterestBearingDomesticDepositMoneyMarket
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of interest-bearing domestic savings deposit liabilities. Saving deposits bear interest and have no stated maturity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.12) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_InterestBearingDomesticDepositSavings
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of money in noninterest-bearing domestic accounts that entitle the depositor to withdraw funds at any time without prior notice, also known as demand deposits. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.12) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_NoninterestBearingDomesticDepositDemand
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Percentage of interest-bearing domestic checking demand deposit liabilities to total deposit liabilities. + References No definition available. + Details
Name: | us-gaap_PercentageOfInterestBearingDomesticDepositsToDepositsChecking
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of interest-bearing domestic money market demand account deposit liabilities to total deposit liabilities. + References No definition available. + Details
Name: | us-gaap_PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of interest-bearing domestic savings deposit liabilities to total deposit liabilities. + References No definition available. + Details
Name: | us-gaap_PercentageOfInterestBearingDomesticDepositsToDepositsSavings
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant