XML 70 R59.htm IDEA: XBRL DOCUMENT v3.20.2
Fair Value of Financial Instruments - Quantitative Information about Unobservable Inputs Used in Recurring and Nonrecurring Level 3 Fair Value Measurements (Detail)
$ in Thousands
Sep. 30, 2020
USD ($)
Dec. 31, 2019
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value $ 259,041 $ 222,293
State and Local Governments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 62,995 54,630
Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value 1,585 1,490
Level 3 [Member] | State and Local Governments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value $ 1,585 $ 1,490
Valuation Technique us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:ValuationTechniqueDiscountedCashFlowMember
Unobservable Inputs us-gaap:MeasurementInputDiscountRateMember us-gaap:MeasurementInputDiscountRateMember
Level 3 [Member] | Collateral Dependent Impaired Loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value $ 8,144 $ 444
Valuation Technique us-gaap:MarketApproachValuationTechniqueMember us-gaap:MarketApproachValuationTechniqueMember
Unobservable Inputs fmao:MeasurementInputCollateralBasedPriceMember fmao:MeasurementInputCollateralBasedPriceMember
Level 3 [Member] | Other Real Estate Owned-Commercial [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value   $ 164
Valuation Technique us-gaap:MarketApproachValuationTechniqueMember us-gaap:MarketApproachValuationTechniqueMember
Unobservable Inputs us-gaap:MeasurementInputAppraisedValueMember us-gaap:MeasurementInputAppraisedValueMember
Level 3 [Member] | Minimum [Member] | State and Local Governments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Discount rate 0 0
Level 3 [Member] | Minimum [Member] | Collateral Dependent Impaired Loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Discount rate 0 0
Level 3 [Member] | Minimum [Member] | Other Real Estate Owned-Commercial [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Discount rate 0 0
Level 3 [Member] | Maximum [Member] | State and Local Governments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Discount rate 5 5
Level 3 [Member] | Maximum [Member] | Collateral Dependent Impaired Loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Discount rate 50 50
Level 3 [Member] | Maximum [Member] | Other Real Estate Owned-Commercial [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Discount rate 0 20
Level 3 [Member] | Weighted Average [Member] | State and Local Governments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Discount rate 1.07 2.52
Level 3 [Member] | Weighted Average [Member] | Collateral Dependent Impaired Loans [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Discount rate 5.99 30.73
Level 3 [Member] | Weighted Average [Member] | Other Real Estate Owned-Commercial [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Discount rate 0 23.31