Basis of Presentation (Policies)	6 Months Ended
Jun. 30, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The unaudited financial information included in this report includes the accounts of FIS and its subsidiaries and has been prepared in accordance with U.S. generally accepted accounting principles and the instructions to Form 10-Q and Article 10 of Regulation S-X. All adjustments considered necessary for a fair presentation have been included. This report should be read in conjunction with the Company's Annual Report on Form 10-K for the year ended December 31, 2025. The preparation of these consolidated financial statements in conformity with United States ("U.S.") generally accepted accounting principles ("GAAP") and the related rules and regulations of the U.S. Securities and Exchange Commission ("SEC" or "Commission") requires our management to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses, and the related disclosure of contingent assets and liabilities. The inputs into management's critical and significant accounting estimates consider the economic impact of inflation and economic growth rates. These estimates may change as new events occur and additional information is obtained. Future actual results could differ materially from these estimates. To the extent that there are differences between these estimates, judgments and assumptions and actual results, our consolidated financial statements will be affected.
Recently Adopted Accounting Guidance and Recent Accounting Guidance Not Yet Adopted	Recently Adopted Accounting Guidance No recently adopted accounting pronouncements had a material impact on our consolidated financial statements or disclosures. Recent Accounting Guidance Not Yet Adopted There have been no material changes to the Company's assessment of recently issued accounting pronouncements from that disclosed in the Company's Annual Report on Form 10‑K for the year ended December 31, 2025. In May 2026, the FASB issued ASU 2026-02, Environmental Credits and Environmental Credit Obligations (Topic 818). The ASU improves the financial accounting for and disclosure of environmental credits and environmental credit obligations by establishing a comprehensive framework for entities that generate, purchase, or receive environmental credits. This guidance is effective for annual periods beginning after December 15, 2027, including interim periods within those fiscal years, with early adoption permitted. The amendments are required to be applied using a modified retrospective approach through a cumulative-effect adjustment to beginning retained earnings, if applicable. The Company is currently evaluating the impact of this ASU on its consolidated financial statements and related disclosures.

Basis of Presentation (Policies)

6 Months Ended

Jun. 30, 2026

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The unaudited financial information included in this report includes the accounts of FIS and its subsidiaries and has been prepared in accordance with U.S. generally accepted accounting principles and the instructions to Form 10-Q and Article 10 of Regulation S-X. All adjustments considered necessary for a fair presentation have been included. This report should be read in conjunction with the Company's Annual Report on Form 10-K for the year ended December 31, 2025.

The preparation of these consolidated financial statements in conformity with United States ("U.S.") generally accepted accounting principles ("GAAP") and the related rules and regulations of the U.S. Securities and Exchange Commission ("SEC" or "Commission") requires our management to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses, and the related disclosure of contingent assets and liabilities. The inputs into management's critical and significant accounting estimates consider the economic impact of inflation and economic growth rates. These estimates may change as new events occur and additional information is obtained. Future actual results could differ materially from these estimates. To the extent that there are differences between these estimates, judgments and assumptions and actual results, our consolidated financial statements will be affected.

Recently Adopted Accounting Guidance and Recent Accounting Guidance Not Yet Adopted

Recently Adopted Accounting Guidance

No recently adopted accounting pronouncements had a material impact on our consolidated financial statements or disclosures.

Recent Accounting Guidance Not Yet Adopted

There have been no material changes to the Company's assessment of recently issued accounting pronouncements from that disclosed in the Company's Annual Report on Form 10‑K for the year ended December 31, 2025.

In May 2026, the FASB issued ASU 2026-02, Environmental Credits and Environmental Credit Obligations (Topic 818). The ASU improves the financial accounting for and disclosure of environmental credits and environmental credit obligations by establishing a comprehensive framework for entities that generate, purchase, or receive environmental credits. This guidance is effective for annual periods beginning after December 15, 2027, including interim periods within those fiscal years, with early adoption permitted. The amendments are required to be applied using a modified retrospective approach through a cumulative-effect adjustment to beginning retained earnings, if applicable. The Company is currently evaluating the impact of this ASU on its consolidated financial statements and related disclosures.