XML 112 R97.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Fair Value of Financial Instruments - Changes in the Level 3 Fair Value Category of Unobservable Inputs (Detail) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |
Beginning Balance | $ 248,492 |  |
Purchases | 60,925 |  | $ 103,320
Sales | 47,029 | $ 57,928 | 91,039
Ending Balance | 235,115 | 248,492 |
State and Local Governments [Member] |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |
Beginning Balance | 74,303 |  |
Ending Balance | 72,066 | 74,303 |
Level 3 [Member] |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |
Beginning Balance | 7,931 |  |
Ending Balance | 7,352 | 7,931 |
Level 3 [Member] | State and Local Governments [Member] |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |
Beginning Balance | 7,931 | 10,346 |
Change in Market Value | (104) | (1,355) |
Purchases | 0 | 0 |
Sales | 0 | 0 |
Payments & Maturities | (475) | (1,060) |
Ending Balance | 7,352 | 7,931 | 10,346
Level 3 [Member] | State and Local Governments [Member] | Tax - Exempt [Member] |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |
Beginning Balance | 6,638 | 8,802 |
Change in Market Value | (259) | (1,104) |
Purchases | 0 | 0 |
Sales | 0 | 0 |
Payments & Maturities | (475) | (1,060) |
Ending Balance | 5,904 | 6,638 | 8,802
Level 3 [Member] | State and Local Governments [Member] | Taxable [Member] |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |
Beginning Balance | 1,293 | 1,544 |
Change in Market Value | 155 | (251) |
Purchases | 0 | 0 |
Sales | 0 | 0 |
Ending Balance | $ 1,448 | $ 1,293 | $ 1,544

X
- Definition Net change in fair market value of available for sale securities. + References No definition available. + Details
Name: | fmao_NetChangeInFairMarketValueOfAvailableForSaleSecurities
Namespace Prefix: | fmao_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Payments and maturities of available for sale securities. + References No definition available. + Details
Name: | fmao_PaymentsAndMaturitiesOfAvailableForSaleSecurities
Namespace Prefix: | fmao_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of debt securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49167202&loc=d3e26610-111562 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -Section 50 -Paragraph 2 -Subparagraph (b)-(g) -URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition The cash outflow to acquire debt securities classified as available-for-sale securities, because they are not classified as either held-to-maturity securities or trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3213-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=49167202&loc=d3e26853-111562 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 + Details
Name: | us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=49167202&loc=d3e26853-111562 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (a),(b) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3179-108585 + Details
Name: | us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_StateAndLocalJurisdictionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxCreditCarryforwardAxis=fmao_TaxExemptMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxCreditCarryforwardAxis=fmao_TaxableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |