Loan deferrals or modifications.

No definition available.

Name:	fraf_LoanDeferralsOrModifications
Namespace Prefix:	fraf_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Number Of Loans Pledged As Collateral

+ References

No definition available.

+ Details

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- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

+ References

+ Details

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- 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.

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- Definition

Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease.

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Balance Type:	debit
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- Definition

Amortized cost excluding accrued interest, of financing receivable with payment default in current period and modified within previous 12 months preceding payment default for debtor experiencing financial difficulty.

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- Definition

Amortized cost of financing receivable modified during period for debtor experiencing financial difficulty.

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- Definition

Amortized cost, before allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

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Loan Quality And Allowance for Credit Losses (Narrative) (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2026 USD ($) loan	Mar. 31, 2025 USD ($)	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)
Financing Receivable, Allowance for Credit Losses [Line Items]
Loan deferrals or modifications	$ 0		$ 0
Loans modified	0		0
Loans to borrowers	0	$ 0
Allowance for loan losses	20,729,000	18,444,000	20,655,000	$ 17,653,000
Reversal of expense	202,000	750,000
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	3,037,000	3,394,000	3,641,000	3,182,000
Reversal of expense	(436,000)	161,000
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	177,000	116,000	155,000	133,000
Reversal of expense	49,000	(4,000)
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	14,580,000	12,480,000	14,042,000	$ 12,004,000
Reversal of expense	538,000	$ 476,000
Collateral Pledged [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Collateral dependent loan	7,900,000
Construction Loans [Member] \| Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Collateral dependent loan			$ 7,100,000
Allowance for loan losses	$ 1,000,000.0
Collateral Dependent [Member] \| Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of loans pledged as collateral \| loan	3
Collateral dependent loan	$ 621,000
Allowance for loan losses	$ 557,000
Collateral Dependent [Member] \| Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of loans pledged as collateral \| loan	1
Collateral dependent loan	$ 233,000
Collateral Dependent [Member] \| Construction Loans [Member] \| Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of loans pledged as collateral \| loan	1
Collateral dependent loan	$ 7,000,000.0
OAEM [Member] \| Related Party Of Bank Director [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Collateral dependent loan	$ 4,200,000