Regulatory matters - Schedule of Bank's Capital Amounts and Ratios (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Consolidated
Common equity Tier 1 capital to risk-weighted assets
Common equity Tier 1 capital to risk-weighted assets, Actual Amount	$ 221,024	$ 205,222
Common equity Tier 1 capital to risk-weighted assets, Actual Ratio	11.95%	11.85%
Common equity Tier 1 capital to risk-weighted assets, Minimum For Capital Adequacy Purposes Amount	$ 83,241	$ 77,930
Common equity Tier 1 capital to risk-weighted assets, Minimum For Capital Adequacy Purposes Ratio	4.50%	4.50%
Tier 1 capital to risk-weighted assets
Tier 1 capital to risk-weighted assets, Actual Amount	$ 221,024	$ 205,222
Tier 1 capital to risk-weighted assets, Actual Ratio	11.95%	11.85%
Tier 1 capital to risk-weighted assets, Minimum For Capital Adequacy Purposes Amount	$ 110,988	$ 103,906
Tier 1 capital to risk-weighted assets, Minimum For Capital Adequacy Purposes Ratio	6.00%	6.00%
Total capital to risk-weighted assets
Total capital to risk-weighted assets, Actual Amount	$ 242,403	$ 224,182
Total capital to risk-weighted assets, Actual Ratio	13.10%	12.95%
Total capital to risk-weighted assets, Minimum For Capital Adequacy Purposes Amount	$ 147,984	$ 138,542
Total capital to risk-weighted assets, Minimum For Capital Adequacy Purposes Ratio	8.00%	8.00%
Tier 1 capital to average assets
Tier 1 capital to average assets, Actual Amount	$ 221,024	$ 205,222
Tier 1 capital to average assets, Actual Ratio	10.03%	9.94%
Tier 1 capital to average assets, Minimum For Capital Adequacy Purposes Amount	$ 88,119	$ 82,564
Tier 1 capital to average assets, Minimum For Capital Adequacy Purposes Ratio	4.00%	4.00%
Peoples Bank
Common equity Tier 1 capital to risk-weighted assets
Common equity Tier 1 capital to risk-weighted assets, Actual Amount	$ 215,027	$ 199,450
Common equity Tier 1 capital to risk-weighted assets, Actual Ratio	11.64%	11.53%
Common equity Tier 1 capital to risk-weighted assets, Minimum For Capital Adequacy Purposes Amount	$ 83,144	$ 77,843
Common equity Tier 1 capital to risk-weighted assets, Minimum For Capital Adequacy Purposes Ratio	4.50%	4.50%
Common equity Tier 1 capital to risk-weighted assets, Minimum to be Well Capitalized under Prompt Corrective Action Provisions Amount	$ 120,097	$ 112,440
Common equity Tier 1 capital to risk-weighted assets, Minimum to be Well Capitalized under Prompt Corrective Action Provisions Ratio	6.50%	6.50%
Tier 1 capital to risk-weighted assets
Tier 1 capital to risk-weighted assets, Actual Amount	$ 215,027	$ 199,450
Tier 1 capital to risk-weighted assets, Actual Ratio	11.64%	11.53%
Tier 1 capital to risk-weighted assets, Minimum For Capital Adequacy Purposes Amount	$ 110,859	$ 103,791
Tier 1 capital to risk-weighted assets, Minimum For Capital Adequacy Purposes Ratio	6.00%	6.00%
Tier 1 capital to risk-weighted assets, Minimum to be Well Capitalized under Prompt Corrective Action Provisions Amount	$ 147,811	$ 138,388
Tier 1 capital to risk-weighted assets, Minimum to be Well Capitalized under Prompt Corrective Action Provisions Ratio	8.00%	8.00%
Total capital to risk-weighted assets
Total capital to risk-weighted assets, Actual Amount	$ 236,406	$ 218,410
Total capital to risk-weighted assets, Actual Ratio	12.80%	12.63%
Total capital to risk-weighted assets, Minimum For Capital Adequacy Purposes Amount	$ 147,811	$ 138,388
Total capital to risk-weighted assets, Minimum For Capital Adequacy Purposes Ratio	8.00%	8.00%
Total capital to risk-weighted assets, Minimum to be Well Capitalized under Prompt Corrective Action Provisions Amount	$ 184,764	$ 172,985
Total capital to risk-weighted assets, Minimum to be Well Capitalized under Prompt Corrective Action Provisions Ratio	10.00%	10.00%
Tier 1 capital to average assets
Tier 1 capital to average assets, Actual Amount	$ 215,027	$ 199,450
Tier 1 capital to average assets, Actual Ratio	9.78%	9.68%
Tier 1 capital to average assets, Minimum For Capital Adequacy Purposes Amount	$ 87,969	$ 82,406
Tier 1 capital to average assets, Minimum For Capital Adequacy Purposes Ratio	4.00%	4.00%
Tier 1 capital to average assets, Minimum to be Well Capitalized under Prompt Corrective Action Provisions Amount	$ 109,962	$ 103,008
Tier 1 capital to average assets, Minimum to be Well Capitalized under Prompt Corrective Action Provisions Ratio	5.00%	5.00%

No definition available.

Name:	pfis_CommonEquityTierOneLeverageCapitalAbstract
Namespace Prefix:	pfis_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Tier 1 Common Equity Risk Based Capital as defined in the regulations.

+ References

No definition available.

+ Details

Name:	pfis_TierOneCommonEquityRiskBasedCapital
Namespace Prefix:	pfis_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum amount of Tier 1 Common Equity Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

+ References

No definition available.

+ Details

Name:	pfis_TierOneCommonEquityRiskBasedCapitalRequiredForCapitalAdequacy
Namespace Prefix:	pfis_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The Tier One minimum Common Equity Capital Ratio ( Tier one Common Equity capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

+ References

No definition available.

+ Details

Name:	pfis_TierOneCommonEquityRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets
Namespace Prefix:	pfis_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of Tier 1 Common Equity Risk Based Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

+ References

No definition available.

+ Details

Name:	pfis_TierOneCommonEquityRiskBasedCapitalRequiredToBeWellCapitalized
Namespace Prefix:	pfis_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The Tier 1 Common Equity capital ratio (Tier 1 Common Equity capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action.

+ References

No definition available.

+ Details

Name:	pfis_TierOneCommonEquityRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Namespace Prefix:	pfis_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Tier 1 Common Equity capital divided by risk weighted assets as defined by regulations.

+ References

No definition available.

+ Details

Name:	pfis_TierOneCommonEquityRiskBasedCapitalToRiskWeightedAssets
Namespace Prefix:	pfis_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of total capital as defined in the regulations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6490092&loc=d3e47304-110998

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1H
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84167132&loc=d3e65071-112826

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=6490092&loc=d3e47080-110998

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1H
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84167132&loc=d3e65071-112826

+ Details

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

- References

No definition available.

+ Details

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

- Definition

The minimum amount of Total Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

+ References

+ Details

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

- Definition

The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84167132&loc=SL5958568-112826

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=84167132&loc=SL5958570-112826

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1H
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84167132&loc=d3e65071-112826

+ Details

Name:	us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of Total Capital required to be categorized as well as capitalized under the regulatory framework for prompt corrective action.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=84167132&loc=SL5958568-112826

+ Details

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

- Definition

The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action.

+ References

+ Details

Name:	us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Total Capital divided by risk weighted assets as defined in the regulations.

+ References

+ Details

Name:	us-gaap_CapitalToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Tier 1 Leverage Capital as defined in the regulations. Also called Core Capital.

+ References

+ Details

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

- References

No definition available.

+ Details

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

- Definition

The minimum amount of Tier 1 Leverage Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

+ References

+ Details

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

- Definition

The minimum amount of Tier 1 Leverage Capital for capital adequacy purposes divided by average assets as defined in the regulations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1H
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84167132&loc=d3e65071-112826

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=84167132&loc=SL5958570-112826

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84167132&loc=SL5958568-112826

+ Details

Name:	us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of Tier 1 Leverage Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

+ References

+ Details

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

- Definition

The amount of Tier 1 Leverage Capital required to be categorized as well capitalized divided by average assets as defined in the regulatory framework for prompt corrective action.

+ References

+ Details

Name:	us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Tier 1 Leverage Capital divided by average assets as defined in the regulations.

+ References

+ Details

Name:	us-gaap_TierOneLeverageCapitalToAverageAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Tier 1 Risk Based Capital as defined in the regulations.

+ References

+ Details

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

- References

No definition available.

+ Details

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

- Definition

The minimum amount of Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

+ References

+ Details

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

- Definition

The minimum Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=84167132&loc=SL5958570-112826

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84167132&loc=SL5958568-112826

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1H
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84167132&loc=d3e65071-112826

+ Details

Name:	us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of Tier 1 Risk Based Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

+ References

+ Details

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

- Definition

The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action.

+ References

+ Details

Name:	us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Tier 1 capital divided by risk weighted assets as defined by regulations.

+ References

+ Details

Name:	us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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

- Details

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