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:	dtr-types:percentItemType
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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826

+ 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

No definition available.

+ 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://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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

- 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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ 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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

+ Details

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

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=fraf_CallDate1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember
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, 2022 USD ($)	Dec. 31, 2021	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	$ 141,800
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 1 Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	0.08		0.06
Tier 1 Leverage Ratio: Well Capitalized Minimum: Ratio	0.05
Total Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	0.10
Capital ratios, capital conservation buffer	0.025%
Subordinated Debt	$ 20,000
Subordinated Debt, Current	15,000
Subordinated Long-term Debt, Noncurrent	5,000
Unsecured Debt	$ 377
Community Bank Leverage Ratio, Minimum	0.09%
Consolidated asset limit on small bank holding companies	$ 3,000,000
Redemption period	5 years
Subordinated Debt [Member] \| Call Date 1 [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Debt Instrument, Term	5 years
Debt Instrument, Interest Rate, Stated Percentage	0.05%
Subordinated Debt [Member] \| Call Date 1 [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.0493%
Subordinated Debt [Member] \| Call Date 2 [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Debt Instrument, Term	10 years
Debt Instrument, Interest Rate, Stated Percentage	0.0525%
Subordinated Debt [Member] \| Call Date 2 [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.0492%
Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Leverage Ratio: Ratio	0.0921	0.0857
Common Equity Tier 1 Risk-based Capital Ratio: Ratio	0.1463	0.1528
Common Equity Tier 1 Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	0.065%	0.065%
Tier 1 Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	0.0800	0.0800
Tier 1 Leverage Ratio: Well Capitalized Minimum: Ratio	0.0500	0.0500
Total Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	0.1000	0.1000
Capital ratios, capital conservation buffer	0.0788%