Summary of significant accounting policies - Additional Information (Details)	3 Months Ended
Mar. 31, 2017 Office
Summary of significant accounting policies
Number of full-service community banking offices	26

The number of full-service community banking offices.

No definition available.

Name:	pfis_NumberOfFullServiceBankingOffices
Namespace Prefix:	pfis_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration