Loan deferrals or modifications.

No definition available.

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

- Definition

Number Of Commercial Loan

+ References

No definition available.

+ Details

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Namespace Prefix:	fraf_
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Balance Type:	na
Period Type:	duration

- Definition

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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+ Details

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Balance Type:	credit
Period Type:	instant

- 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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Balance Type:	na
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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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Balance Type:	debit
Period Type:	duration

- Definition

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

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Balance Type:	debit
Period Type:	duration

- 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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+ Details

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Balance Type:
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- Details

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- Details

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Loan Quality And Allowance for Credit Losses (Narrative) (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) loan	Sep. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Financing Receivable, Allowance for Credit Losses [Line Items]
Loan deferrals or modifications	$ 0		$ 0		$ 0
Number of commercial loans \| loan			2
Loans modified			$ 0		0
Loans to borrowers	0	$ 0	0	$ 0
Construction Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Specific reserve for credit loss	894,000		894,000
Collateral Dependent [Member] \| Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Collateral dependent loan	10,200,000		10,200,000		$ 266,000
Collateral Dependent [Member] \| Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Collateral dependent loan	7,300,000		7,300,000
Collateral Dependent [Member] \| Hotel Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Collateral dependent loan	2,900,000		2,900,000
OAEM [Member] \| Related Party Of Bank Director [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Collateral dependent loan	$ 4,700,000		$ 4,700,000