XML 77 R70.htm IDEA: XBRL DOCUMENT
v3.24.1.u1

Qualified Affordable Housing Project Investments - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended |
--- | --- | ---
Mar. 31, 2024 | Dec. 31, 2023
Investments in Affordable Housing Projects [Abstract] |  |
Qualified affordable housing project investments | $ 3,900 | $ 2,400
Funded commitments related to the investments in qualified affordable housing projects |  | $ 4,000
Unfunded commitments related to the investments in qualified affordable housing projects | 1,400 |
Amortization expense recognized with qualified affordable housing project | 110 |
Affordable housing tax credits from other tax benefits | $ 108 |
Impairment losses related to investments in qualified affordable housing projects | no |

X
- Definition Funded commitments related to the investments in qualified affordable housing projects. + References No definition available. + Details
Name: | fmao_FundedCommitmentsRelatedToTheInvestmentsInQualifiedAffordableHousingProjects
Namespace Prefix: | fmao_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Unfunded commitments related to the investments in qualified affordable housing projects. + References No definition available. + Details
Name: | fmao_UnfundedCommitmentsRelatedToTheInvestmentsInQualifiedAffordableHousingProjects
Namespace Prefix: | fmao_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Description of write-down from impairment of an investment in a qualified affordable housing project. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (f) -SubTopic 740 -Topic 323 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481543/323-740-50-2 + Details
Name: | us-gaap_AffordableHousingProjectInvestmentNatureOfWriteDown
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of affordable housing tax credits and other tax benefits recognized. + References Reference 1: http://www.xbrl.org/2003/role/recommendedDisclosureRef -Topic 323 -SubTopic 740 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481543/323-740-50-2 + Details
Name: | us-gaap_AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of amortization expense of investment in qualified affordable housing projects. + References Reference 1: http://www.xbrl.org/2003/role/recommendedDisclosureRef -Topic 323 -SubTopic 740 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481543/323-740-50-2 + Details
Name: | us-gaap_AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsInAffordableHousingProjectsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of commitment or contingent commitments to qualified affordable housing project investments. + References Reference 1: http://www.xbrl.org/2003/role/recommendedDisclosureRef -Topic 323 -SubTopic 740 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481543/323-740-50-2 + Details
Name: | us-gaap_QualifiedAffordableHousingProjectInvestmentsCommitment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant