XML 114 R100.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Federal Funds Purchased and Securities Sold Under Agreement to Repurchase - Daily Securities Sold under Agreement to Repurchase (Detail) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023
Schedule of Trading Securities and Other Trading Assets [Line Items] |  |
Amount Outstanding at End of Period | $ 27,200 |
Securities Sold under Agreements to Repurchase [Member] |  |
Schedule of Trading Securities and Other Trading Assets [Line Items] |  |
Amount Outstanding at End of Period | $ 27,218 | $ 28,218
Weighted Average Rate End of Period | 0.99% | 0.98%
Maximum Amount Borrowings Outstanding Month End | $ 27,218 | $ 28,968
Approximate Average Outstanding in Period | $ 27,574 | $ 28,918
Approximate Weighted Average Interest Rate For the Period | 4.00% | 3.97%
Daily Securities Sold Under Agreement to Repurchase [Member] |  |
Schedule of Trading Securities and Other Trading Assets [Line Items] |  |
Weighted Average Rate End of Period | 0.00% | 0.00%
Maximum Amount Borrowings Outstanding Month End | $ 523 | $ 1,694
Approximate Average Outstanding in Period | $ 79 | $ 1,176
Approximate Weighted Average Interest Rate For the Period | 3.77% | 1.19%

X
- Definition Securities sold under agreements to repurchase average outstanding amount in period. + References No definition available. + Details
Name: | fmao_SecuritiesSoldUnderAgreementsToRepurchaseAverageOutstandingAmountInPeriod
Namespace Prefix: | fmao_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Securities sold under agreements to repurchase maximum monthly outstanding amount. + References No definition available. + Details
Name: | fmao_SecuritiesSoldUnderAgreementsToRepurchaseMaximumMonthlyOutstandingAmount
Namespace Prefix: | fmao_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Securities sold under agreements to repurchase weighted average interest rate. + References No definition available. + Details
Name: | fmao_SecuritiesSoldUnderAgreementsToRepurchaseWeightedAverageInterestRate
Namespace Prefix: | fmao_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Securities sold under agreements to repurchase weighted average interest rate during period. + References No definition available. + Details
Name: | fmao_SecuritiesSoldUnderAgreementsToRepurchaseWeightedAverageInterestRateDuringPeriod
Namespace Prefix: | fmao_
Data Type: | dtr-types:percentItemType
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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-6B + Details
Name: | us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(13)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.12-12A(Column A)(Footnote 2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-12(Column A)(Footnote 2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14(Column A)(Footnote 2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-12B(Column A)(Footnote 4)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-3 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483466/210-20-50-3 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(m)(1)(i)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(m)(1)(ii)(A)(i)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-10 + Details
Name: | us-gaap_SecuritiesSoldUnderAgreementsToRepurchase
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_PledgingPurposeAxis=us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CashAndCashEquivalentsAxis=fmao_DailySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |