Accounting Policies, by Policy (Policies)	9 Months Ended
Accounting Policies, by Policy (Policies)	Sep. 30, 2025
Accounting Policies [Abstract]
Basis of Presentation	Citizens Financial Services, Inc. (individually and collectively with its direct and indirect subsidiaries, the “Company”) is a Pennsylvania corporation and the holding company of its wholly owned subsidiary, First Citizens Community Bank (the “Bank”), and of the Bank’s wholly owned subsidiary, First Citizens Insurance Agency, Inc. (“First Citizens Insurance”). During 2024, the Company and Bank began the process to terminate the corporate existence of CZFS Acquisition Company, LLC, a wholly-owned subsidiary of the Company, and 1^st Realty of PA LLC, a wholly-owned subsidiary of the Bank. The accompanying consolidated financial statements have been prepared pursuant to rules and regulations of the Securities and Exchange Commission (“SEC”) and in conformity with U.S. generally accepted accounting principles. Because this report is based on an interim period, certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles have been condensed or omitted. Certain of the prior year amounts have been reclassified to conform with the current year presentation. Such reclassifications had no effect on net income or stockholders’ equity. All material inter‑company balances and transactions have been eliminated in consolidation. In the opinion of management of the Company, the accompanying interim consolidated financial statements at September 30, 2025 and for the periods ended September 30, 2025 and 2024 include all adjustments, consisting of only normal recurring adjustments, necessary for a fair presentation of the financial condition and the results of operations at the dates and for the periods presented. In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheet and of revenues and expenses for the periods covered by the Consolidated Statement of Income. The financial performance reported for the Company for the three and nine month periods ended September 30, 2025 is not necessarily indicative of the results to be expected for the full year. This information should be read in conjunction with the Company’s audited consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2024.
Recent Accounting Pronouncements	In November 2024, the FASB issued ASU 2024-03, Income Statement – Reporting Comprehensive Income – Expense Disaggregation Disclosures. This ASU requires disclosure in the notes to financial statements of specified information about certain costs and expenses. Specific disclosures are required for (a) purchases of inventory, (b) employee compensation, (c) depreciation, (d) intangible asset amortization, and (e) depreciation, depletion, and amortization recognized as part of oil and gas producing activities. The amendments in this Update do not change or remove current expense disclosure requirements. However, the amendments affect where this information appears in the notes to financial statements because entities are required to include certain current disclosures in the same tabular format disclosure as the other disaggregation requirements in the amendments. The amendments in ASU 2024-03 apply only to public business entities and are effective for fiscal years beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027, with early adoption permitted. The Company is currently evaluating the impact of this new guidance on its financial statements. In December 2024, the FASB issued ASU 2024-04, Debt – Debt with Conversion and Other Options (Subtopic 470-20): Induced Conversions of Convertible Debt Instruments. This new guidance clarifies the assessment of whether a transaction should be accounted for as an induced conversion or extinguishment of convertible debt when changes are made to conversion features as part of an offer to settle the instrument. The ASU requires entities to apply a preexisting contract approach. To qualify for induced conversion accounting under this approach, the inducement offer is required to preserve the form of consideration and result in an amount of consideration that is no less than that issuable pursuant to the preexisting conversion privileges. The guidance is effective for fiscal years beginning after December 15, 2025, with early adoption permitted, and it can be adopted either on a prospective or retrospective basis. This Update is not expected to have a significant impact on the Company’s financial statements. In January 2025, the FASB issued ASU 2025-01, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40), which revises the effective date of ASU 2024-03 (on disclosures about disaggregation of income statement expenses) “to clarify that all public business entities are required to adopt the guidance in annual reporting periods beginning after December 15, 2026, and interim periods within annual reporting periods beginning after December 15, 2027.” Entities within the ASU’s scope are permitted to early adopt the ASU. The Company is currently evaluating the impact of this new guidance on its financial statements. In January 2025, the FASB issued ASU 2025-02, Liabilities (405): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 122. This ASU was issued pursuant to SEC Staff Accounting Bulletin No. 122, which rescinds the interpretive guidance included in Section FF of Topic 5 in the Staff Accounting Bulletin series entitled Accounting for Obligations to Safeguard Crypto-Assets an Entity Holds for its Platform Users. This ASU has no impact on non-public business entities and is effective for fiscal years beginning after December 15, 2024. This Update is not expected to have a significant impact on the Company’s financial statements. In May 2025, the FASB issued ASU 2025-03, Determining the Accounting Acquirer in the Acquisition of a Variable Interest Entity, which revises the guidance in ASC 805 on identifying the accounting acquirer in a business combination in which the legal acquiree is a variable interest entity (VIE). The reporting entity can determine that a transaction in which the legal acquiree is a VIE represents a reverse acquisition in which the legal acquirer is identified as the acquiree for accounting purposes. ASU 2025-03 is effective for fiscal years beginning after December 15, 2026, including interim periods within those fiscal years. Early adoption is permitted. The amendments in ASU 2025-03 must be applied prospectively to any business combination that occurs after the initial adoption date. This Update is not expected to have a significant impact on the Company’s financial statements. In May 2025, the FASB issued ASU 2025-04, Compensation – Stock Compensation (Topic 718) and Revenue from Contracts With Customers (Topic 606): Clarifications to Share-Based Consideration Payable to a Customer, which clarifies the accounting for share-based consideration payable to a customer under ASC 718 and ASC 606. The amendments refine key aspects of the guidance, including the definition of “performance condition” as well as the measurement requirements and the treatment of forfeitures. The amendments will be effective for annual reporting periods beginning after December 15, 2026, including interim periods within those annual periods. Early adoption is permitted for financial statements that have not yet been issued. The Company is currently evaluating the impact of this new guidance on its financial statements. Other accounting standards that have been issued by the FASB or other standards-setting bodies are not currently expected to have a material effect on the Company’s consolidated financial position, results of operations or cash flows.