Capital Ratios (Schedule Of The Total Risk-based, Tier 1 Risk-based And Tier 1 Leverage Requirements) (Details)	Jun. 30, 2021	Dec. 31, 2020
Franklin Financial Services Corporation [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Risk-based Capital Ratio: Ratio	15.16	14.32
Tier 1 Risk-based Capital Ratio: Ratio	15.16	14.32
Total Risk-based Capital Ratio: Ratio	18.52	17.69
Tier 1 Leverage Ratio: Ratio	8.53	8.69
Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Risk-based Capital Ratio: Ratio	15.02	14.07
Common Equity Tier 1 Risk-based Capital Ratio: Adequately Capitalized Minimum: Ratio	4.50
Common Equity Tier 1 Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	6.50%
Tier 1 Risk-based Capital Ratio: Ratio	15.02	14.07
Tier 1 Risk-based Capital Ratio: Adequately Capitalized Minimum: Ratio	6.00
Tier 1 Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	8.00
Total Risk-based Capital Ratio: Ratio	16.28	15.33
Total Risk-based Capital Ratio: Adequately Capitalized Minimum: Ratio	8.00
Total Risk-based Capital Ratio: Well Capitalized Minimum: Ratio	10.00
Tier 1 Leverage Ratio: Ratio	8.46	8.54
Tier 1 Leverage Ratio: Adequately Capitalized Minimum: Ratio	4.00
Tier 1 Leverage Ratio: Well Capitalized Minimum: Ratio	5.00

Tangible Capital Required For Well Capitalized To Tangible Assets

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Ratio of minimum total risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1B
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Ratio of minimum tangible capital to tangible assets required for capital adequacy as defined by regulatory framework.

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