XML 95 R81.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Federal Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017
Income Taxes [Line Items] |  |
Net tax benefit related statutory federal income tax rate |  | $ 8
Scenario, Forecast [Member] |  |
Income Taxes [Line Items] |  |
Federal statutory income tax rate | 21.00% |

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 Amount of current state, local, and federal tax expense (benefit) pertaining to income (loss) from continuing operations. + References No definition available. + Details
Name: | us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 6.I) -URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319 + Details
Name: | us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |