Cover - USD ($)	12 Months Ended
	Dec. 31, 2025	Mar. 03, 2026	Jun. 30, 2025
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Financial Statement Error Correction [Flag]	false
Entity Interactive Data Current	Yes
ICFR Auditor Attestation Flag	true
Amendment Flag	false
Document Period End Date	Dec. 31, 2025
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Entity Information [Line Items]
Entity Registrant Name	CITIZENS FINANCIAL SERVICES, INC.
Entity Central Index Key	0000739421
Entity File Number	000-13222
Entity Tax Identification Number	23-2265045
Entity Incorporation, State or Country Code	PA
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Public Float			$ 264,808,000
Entity Contact Personnel [Line Items]
Entity Address, Address Line One	15 South Main Street
Entity Address, City or Town	Mansfield
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	16933
Entity Phone Fax Numbers [Line Items]
City Area Code	570
Local Phone Number	662-2121
Entity Listings [Line Items]
Title of 12(b) Security	Common Stock, Par value $1.00 per share
Trading Symbol	CZFS
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		4,807,219