XML 58 R47.htm IDEA: XBRL DOCUMENT
v3.20.2

Loans (Impaired Loans) - Additional Information (Detail) | 1 Months Ended | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
May 31, 2020 Loan | Sep. 30, 2020 USD ($) Loan | Jun. 30, 2020 Contract | Sep. 30, 2019 USD ($) Contract | Sep. 30, 2020 USD ($) Contract Loan | Sep. 30, 2019 USD ($) Contract Loan | Dec. 31, 2019 USD ($) Loan
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |
Additional funds available to be advanced in connection with impaired loans |  | $ 1,200,000 |  |  | $ 1,200,000 |  |
Impaired loans classified as troubled debt restructured |  | $ 6,400,000 |  | $ 1,100,000 | $ 6,400,000 | $ 1,100,000 | $ 1,000,000.0
Number of contracts modified | Loan |  | 1 |  |  | 6 |  | 5
TDR impaired loans paid off | Loan | 1 |  |  |  |  | 0 |
TDR loans, subsequently defaulted during the period |  | 0 |  | 0 | 0 | 0 |
Maximum time for re-evaluation (in months) |  |  |  |  | 12 months |  |
Re-evaluation period for real estate |  |  |  |  | 2 years |  |
Unsecured consumer loans, credit card credits and overdraft lines of credit reach |  |  |  |  |  | 90 days |
Delinquent period for charging down consumer loans |  |  |  |  |  | 120 days |
Delinquent period for charging down commercial and agricultural credits |  |  |  |  |  | 120 days |
Foreclosed residential real estate property |  | $ 206,000 |  |  | $ 206,000 |  | $ 214,000
Commercial Real Estate [Member] |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |
Impaired loans classified as troubled debt restructured |  | 481,000 |  |  | $ 481,000 |  |
Number of contracts modified | Contract |  |  |  |  | 2 |  |
TDR impaired loans paid off | Loan |  |  |  |  | 1 |  |
Consumer Real Estate [Member] |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |
Number of contracts modified | Contract |  |  |  | 1 |  | 1 |
Foreclosed residential real estate property |  | 71,000 |  | $ 187,000 | $ 71,000 | $ 187,000 |
Residential real estate properties foreclosure proceedings |  | $ 849,000 |  | $ 379,000 | $ 849,000 | $ 379,000 |
Principal Forgiveness [Member] |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |
Number of contracts modified | Contract |  |  |  |  | 0 |  |
Payment Changes from Monthly Payment to Principal and Interest at Maturity [Member] |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |
Number of contracts modified | Contract |  |  |  |  | 2 |  |
Loan maturity date |  |  |  |  | Jun. 19, 2020 |  |
Rate Concession Along With the Amortization Extended [Member] |  |  |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |  |  |
Number of contracts modified | Contract |  |  | 3 |  |  |  |

X
- Definition Additional funds available to be advanced in connection with impaired loans. + References No definition available. + Details
Name: | fmao_AdditionalFundsAvailableToBeAdvancedInConnectionWithImpairedLoans
Namespace Prefix: | fmao_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Delinquent period for charging down commercial and agricultural credits. + References No definition available. + Details
Name: | fmao_DelinquentPeriodForChargingDownCommercialAndAgriculturalCredits
Namespace Prefix: | fmao_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Delinquent period for charging down consumer loans + References No definition available. + Details
Name: | fmao_DelinquentPeriodForChargingDownConsumerLoans
Namespace Prefix: | fmao_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Financing receivables impaired number of troubled debt restructuring write down. + References No definition available. + Details
Name: | fmao_FinancingReceivablesImpairedNumberOfTroubledDebtRestructuringWriteDown
Namespace Prefix: | fmao_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum time for reevaluation. + References No definition available. + Details
Name: | fmao_MaximumTimeForReevaluation
Namespace Prefix: | fmao_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Re evaluation period for real estate. + References No definition available. + Details
Name: | fmao_ReEvaluationPeriodForRealEstate
Namespace Prefix: | fmao_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Unsecured consumer loans credit card credits and overdraft. + References No definition available. + Details
Name: | fmao_UnsecuredConsumerLoansCreditCardCreditsAndOverdraft
Namespace Prefix: | fmao_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_DebtInstrumentMaturityDate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of financing receivable modified as troubled debt restructuring. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554 + Details
Name: | us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953682-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 35 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL49126937-111524 + Details
Name: | us-gaap_MortgageLoansInProcessOfForeclosureAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of land and buildings obtained through foreclosure proceedings or defeasance in full or partial satisfaction of a debt arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5162-111524 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4437-111522 + Details
Name: | us-gaap_RealEstateAcquiredThroughForeclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=us-gaap_PrincipalForgivenessMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=fmao_PaymentChangesFromMonthlyPaymentToPrincipalAndInterestAtMaturityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=fmao_RateConcessionAlongWithAmortizationExtendedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |