XML 110 R95.htm IDEA: XBRL DOCUMENT
v3.22.4

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Perpetual Federal Savings Bank [Member] |  |
Income Taxes [Line Items] |  |
Operating loss carryforwards |  | $ 377,807
Deferred taxes business combination allocated to additional paid in capital |  | $ 2,779,000
Unrecognized deferred taxes | $ 1,040,000 |
Peoples Federal Savings and Loan [Member] |  |
Income Taxes [Line Items] |  |
Operating loss carryforwards | 2,638,002 |
Operating loss carryforward at acquisition | 2,789,124 |
Deferred taxes business combination allocated to additional paid in capital | $ 2,174,000 |

X
- Definition Deferred taxes business combination allocated to additional paid in capital. + References No definition available. + Details
Name: | fmao_DeferredTaxesBusinessCombinationAllocatedToAdditionalPaidInCapital
Namespace Prefix: | fmao_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Income Taxes [Line Items] + References No definition available. + Details
Name: | fmao_IncomeTaxesLineItems
Namespace Prefix: | fmao_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Operating loss carryforward at acquisition. + References No definition available. + Details
Name: | fmao_OperatingLossCarryforwardAtAcquisition
Namespace Prefix: | fmao_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32559-109319 + Details
Name: | us-gaap_OperatingLossCarryforwards
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of unrecognized tax benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 10B -URI https://asc.fasb.org/extlink&oid=123427490&loc=SL37586934-109318 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=121826272&loc=SL6600010-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=fmao_PerpetualFederalSavingBankMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=fmao_PeoplesFederalSavingsAndLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |