Capital Ratios, Capital Conservation Buffer

No definition available.

Name:	fraf_CapitalRatiosCapitalConservationBuffer
Namespace Prefix:	fraf_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Community Bank Leverage Ratio, Minimum

+ References

No definition available.

+ Details

Name:	fraf_CommunityBankLeverageRatioMinimum
Namespace Prefix:	fraf_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Consolidated Asset Limit On Small Bank Holding Companies

+ References

No definition available.

+ Details

Name:	fraf_ConsolidatedAssetLimitOnSmallBankHoldingCompanies
Namespace Prefix:	fraf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Debt Instrument, Redemption Period

+ References

No definition available.

+ Details

Name:	fraf_DebtInstrumentRedemptionPeriod
Namespace Prefix:	fraf_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Tangible Capital Required For Well Capitalized To Tangible Assets

+ References

No definition available.

+ Details

Name:	fraf_TangibleCapitalRequiredForWellCapitalizedToTangibleAssets
Namespace Prefix:	fraf_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Ratio of minimum total risk-based capital to risk-weighted assets categorized as well capitalized as defined by regulatory framework for prompt corrective action.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477270/942-505-50-1

+ Details

Name:	us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
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.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477270/942-505-50-1B

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477270/942-505-50-1

+ Details

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

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(a)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of dividends that can be declared or paid without approval of regulatory agency.

+ References

No definition available.

+ Details

Name:	us-gaap_StatutoryAccountingPracticesStatutoryAmountAvailableForDividendPaymentsWithoutRegulatoryApproval
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-SubTopic 10
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

+ Details

Name:	us-gaap_SubordinatedDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The portion of the carrying value of subordinated debt as of the balance sheet date that is scheduled to be repaid within one year or in the normal operating cycle, if longer. Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets.

+ References

+ Details

Name:	us-gaap_SubordinatedDebtCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of collateralized/uncollateralized debt obligation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion. Subordinated debt places a lender in a lien position behind the primary lender of the company.

+ References

+ Details

Name:	us-gaap_SubordinatedLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Ratio of tangible capital to tangible assets as defined by regulatory framework.

+ References

+ Details

Name:	us-gaap_TangibleCapitalToTangibleAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Ratio of minimum Tier 1 leverage capital to average assets categorized as well capitalized as defined by regulatory framework for prompt corrective action.

+ References

+ Details

Name:	us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Ratio of Tier 1 capital to average assets as defined by regulatory framework.

+ References

+ Details

Name:	us-gaap_TierOneLeverageCapitalToAverageAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Ratio of minimum Tier 1 risk-based capital to risk-weighted assets categorized as well capitalized as defined by regulatory framework for prompt corrective action.

+ References

+ Details

Name:	us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-SubTopic 10
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

+ Details

Name:	us-gaap_UnsecuredDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=fraf_MaturingSeptember12030Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=fraf_MaturingSeptember12035Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodFiveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SubordinatedDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=fraf_CallDate2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=srt_SubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Regulatory Matters (Narrative) (Details) $ in Thousands	12 Months Ended
Regulatory Matters (Narrative) (Details) $ in Thousands	Dec. 31, 2025 USD ($)	Dec. 31, 2024	Dec. 31, 2015
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments without Regulatory Approval	$ 177,900
Capital ratios, capital conservation buffer	2.50%
Unsecured Debt	$ 155
Community Bank Leverage Ratio, Minimum	9.00%
Consolidated asset limit on small bank holding companies	$ 3,000,000
Tier 1 Leverage Ratio: Ratio	0.06
Common Equity Tier 1 Risk-based Capital Ratio: Ratio	0.10
Common Equity Tier 1 Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	0.065
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	0.05
Tier 1 Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	0.08		0.06
Total Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	0.10
Redemption period	5 years
Maturing September 1, 2030 [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Subordinated Debt, Current	$ 6,000
Maturing September 1, 2035 [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Subordinated Long-Term Debt, Noncurrent	$ 5,000
Through September 1, 2025 [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Interest rate	4.93%
Through June 29, 2030 [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Subordinated Long-Term Debt, Noncurrent	$ 5,000
Interest rate	5.25%
Subordinated Notes [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Subordinated Debt	$ 11,000
Subordinated Notes [Member] \| Call Date 2 [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	4.92%
Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital ratios, capital conservation buffer	5.27%
Tier 1 Leverage Ratio: Ratio	0.0857	0.0820
Common Equity Tier 1 Risk-based Capital Ratio: Ratio	0.1202	0.1171
Common Equity Tier 1 Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	0.0650	0.0650
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	0.0500	0.0500
Tier 1 Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	0.0800	0.0800
Total Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	0.1000	0.1000