Debt - Schedule of Principal Maturities of Long-Term Debt (Details) - FIS Credit Agreements $ in Millions	Sep. 30, 2025 USD ($)
Debt Instrument
2025	$ 751
2026	1,284
2027	1,727
2028	1,736
2029	604
Thereafter	5,099
Total principal payments	11,201
Other debt per the long-term debt table	(274)
Total long-term debt, including current portion	$ 10,927

Long-term Debt, Excluding Unamortized Discount (Premium)

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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