Loan Quality (Narrative) (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Period in which consumer loans are substandard, in days	90 days
Loans and Leases Receivable, Gross, Carrying Amount	$ 726,531,000	$ 723,413,000
Non-accrual loans	12,291,000	24,643,000
Increase in loans	4,506,000	(26,375,000)	(3,938,000)
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	752,000	96,000	800,000
Impaired loans	26,600,000	30,900,000
Properties in foreclosure	763,000fraf_PropertiesInForeclosure	1,000fraf_PropertiesInForeclosure
Charge-offs	1,573,000	3,972,000	4,717,000
Historical loss experience factor for general allocation of gross loans, percent	1.00%	0.99%
Loans Receivable, Qualitative Factor Basis Spread	0.375%
Loans Receivable, Basis Spread on Variable Rate	0.215%
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	6,154,000	8,580,000
Charge-offs	189,000	162,000	236,000
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	326,482,000	329,373,000
Non-accrual loans	8,430,000	19,001,000
Charge-offs	408,000	2,855,000	3,298,000
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	179,071,000	170,327,000
Non-accrual loans	1,637,000	2,398,000
Charge-offs	644,000	363,000	861,000
Watch List [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	40,500,000	76,300,000
Maximum [Member] \| Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired loans balances, added to general allocation pool	250,000
Credit 5 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Charge-offs	(549,000)
Credit 6 [Member] \| Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Non-accrual loans	729,000
Credit 6 [Member] \| Watch List [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	17,900,000
Credit 7 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	22,500,000
Decrease In Loans Receivables	$ 34,800,000

Historical Loss Experience Factor For General Allocation Of Gross Loans

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- Definition

Impaired Loans Balances Added To General Allocation Pool

+ References

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Increase Decrease In Loans Receivables

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Loans Receivable, Qualitative Factor Basis Spread

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- Definition

Period In Which Consumer Loans Are Substandard In Days

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Properties in foreclosure

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- Definition

Amount of direct write-downs of financing receivables charged against the allowance.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

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- Definition

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 7

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- Definition

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 50

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

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- Definition

Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

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-Section 50

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- Definition

The percentage points (also referred to as 'margin') added to the reference rate as stated in the loan agreement and used to compute the variable rate on the loans receivable. For instance, the loan agreement might state that the interest rate the borrower is obligated to pay is the London Interbank Offered Rate (LIBOR) plus three quarters (3/4) of a percentage point adjusted quarterly (each three months). LIBOR in this example is the index or reference rate, 3/4 percentage point is the margin, the reference rate plus the margin is the fully indexed rate. This element would be used to report separately the margin.

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- Definition

The net cash outflow or inflow for the increase (decrease) in the beginning and end of period of loan and lease balances which are not originated or purchased specifically for resale. Includes cash payments and proceeds associated with (a) loans held-for-investment, (b) leases held-for-investment, and (c) both.

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