Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Nov. 04, 2024
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Registrant Name	PATHFINDER BANCORP, INC.
Entity Central Index Key	0001609065
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity File Number	001-36695
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	38-3941859
Entity Address, Address Line One	214 West First Street
Entity Address, City or Town	Oswego
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	13126
City Area Code	315
Local Phone Number	343-0057
Title of each class	Common Stock, $0.01 par value
Trading Symbol	PBHC
Name of each exchange on which registered	NASDAQ
Voting Common Stock [Member]
Document Information [Line Items]
Entity Common Stock Shares Outstanding		4,719,788
Series A Nonvoting Common Stock [Member]
Document Information [Line Items]
Entity Common Stock Shares Outstanding		1,380,283