XML 99 R85.htm IDEA: XBRL DOCUMENT v3.8.0.1

Employee Benefit Plans - Additional Information (Detail) $ in Thousands		12 Months Ended
	Sep. 20, 2017	Dec. 31, 2017 USD ($) Employees shares	Dec. 31, 2016 USD ($) Employees shares	Dec. 31, 2015 USD ($) Employees shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum percentage of eligible compensation on a pre-tax basis for eligible employees to save		1.00%
Employee contribution matching percentage		50.00%
Percentage of total eligible compensation, contribution by Bank, maximum limit		4.00%
Vesting percentage in participant's deferral contributions and employer matching contributions		100.00%
Vesting period		6 years
Employer matching contribution and the discretionary contribution | $		$ 972	$ 877	$ 835
Restricted stock awards, shares issued		32,000	32,300	32,000
Number of employees, received the stock | Employees			4
Share stock split ratio	2
Expense for restricted stock awards | $		$ 507	$ 402	$ 314
Awards grants originated in 2012, 2013 and 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of employees, received the stock | Employees				1
One employee received shares from awards granted due to retirement				500
Number of shares paid to estate of deceased employee				650
Awards grants originated in 2013, 2014 and 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of employees, received the stock | Employees			4
Four employees received shares from awards granted due to retirement			2,394
Awards grants originated in 2014, 2015 and 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of employees, received the stock | Employees		1
One employee received shares from awards granted due to retirement		640
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Stock issued to number of employees | Employees		74	74	67
Shares vest under the plan		100.00%	100.00%	100.00%
Shares forfeited due to employee termination		1,080	1,546	200
Number of shares vested		24,870	22,444	20,590
Number of employees, received the stock | Employees		52	45	45
Compensation expense | $		$ 507	$ 402	$ 314
Unrecognized compensation cost related to the nonvested portion of restricted stock awards under the plan | $		$ 1,100
Restricted Stock Awards [Member] | 2011 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares vested				19,440
Restricted Stock Awards [Member] | 2013 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares vested			20,050
Restricted Stock Awards [Member] | 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares vested		24,230

X

- Definition

Minimum Percentage Of Eligible Compensation On Pre Tax Basis For Eligible Employees To Save

+ References

No definition available.

+ Details

Name:	fmao_MinimumPercentageOfEligibleCompensationOnPreTaxBasisForEligibleEmployeesToSave
Namespace Prefix:	fmao_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of awards granted to four employees on retirement.

+ References

No definition available.

+ Details

Name:	fmao_NumberOfAwardsGrantedToFourEmployeesOnRetirement
Namespace Prefix:	fmao_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number Of Awards Granted To One Employee On Retirement

+ References

No definition available.

+ Details

Name:	fmao_NumberOfAwardsGrantedToOneEmployeeOnRetirement
Namespace Prefix:	fmao_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Share Vested Percentage

+ References

No definition available.

+ Details

Name:	fmao_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareVestedPercentage
Namespace Prefix:	fmao_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Share Based Compensation Arrangement By Share Based Payment Award Number Of Employee Share Issued

+ References

No definition available.

+ Details

Name:	fmao_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfEmployeeShareIssued
Namespace Prefix:	fmao_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Share Based Compensation Arrangement By Share Based Payment Award Number Of Employees

+ References

No definition available.

+ Details

Name:	fmao_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfEmployees
Namespace Prefix:	fmao_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Shares paid to estate of deceased employee upon retirement.

+ References

No definition available.

+ Details

Name:	fmao_SharesPaidToEstateOfDeceasedEmployeeUponRetirement
Namespace Prefix:	fmao_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

+ Details

Name:	us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of discretionary contributions made by an employer to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Percentage of employer's matching contributions to a defined contribution plan that vests in a given year.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployersMatchingContributionAnnualVestingPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The noncash expense that represents the cost of restricted stock or unit distributed to employees as compensation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

+ Details

Name:	us-gaap_RestrictedStockExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(2)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
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

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Total number of shares issued during the period, including shares forfeited, as a result of Restricted Stock Awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB TOPIC 4.C)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770

+ Details

Name:	us-gaap_StockholdersEquityNoteStockSplitConversionRatio1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_AwardDateAxis=fmao_AwardGrantsOriginatedInPeriodOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_AwardDateAxis=fmao_AwardGrantsOriginatedInPeriodTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_AwardDateAxis=fmao_AwardGrantsOriginatedInPeriodThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_AwardDateAxis=fmao_YearTwoThousandElevenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_AwardDateAxis=fmao_YearTwoThousandThirteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_AwardDateAxis=fmao_YearTwoThousandFourteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: