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- References

No definition available.

Name:	fmcb_FinancingReceivableModificationsTroubledDebtRestructuredLoansAbstract
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The amount of specific reserve allocated to financing receivable modified as troubled debt restructuring.

No definition available.

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- References

No definition available.

Name:	fmcb_LoansByClassModifiedAsTroubledDebtRestructuredLoansAbstract
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Represents the threshold period after which loan is considered to be in payment default, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

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Number of financing receivables that have been modified by troubled debt restructurings.

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Amount, after troubled debt restructuring, of modified financing receivable.

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Amount, before troubled debt restructuring, of financing receivable to be modified.

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Amount of financing receivable modified as troubled debt restructuring.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=118939409&loc=d3e18845-111554

Name:	us-gaap_FinancingReceivableModificationsRecordedInvestment
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Data Type:	xbrli:monetaryItemType
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Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953682-111524

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Reflects the amount of the write-down related to a troubled debt restructuring.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=118939409&loc=d3e18845-111554

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Data Type:	xbrli:monetaryItemType
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Amount of unfunded portion of contractual agreement to lend funds to borrower for financing receivable modified as troubled debt restructuring.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118939409&loc=d3e18794-111554

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityMember
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Data Type:	na
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Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=fmcb_AgriculturalRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
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Period Type:

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=fmcb_ResidentialFirstMortgagesPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
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