Debt - Schedule of Short-Term Debt (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2025	Dec. 31, 2024
Short-term Debt
Total Short-term borrowings	$ 1,108	$ 636
Commercial Paper
Short-term Debt
Commercial paper	$ 4,500
Commercial Paper \| FIS Credit Agreements \| Euro-commercial paper notes ("ECP Notes")
Short-term Debt
Short term debt, weighted average interest rate	2.60%
Maturities	183 days
Commercial paper	$ 108	104
Commercial Paper \| FIS Credit Agreements \| U.S. commercial paper notes ("USCP Notes")
Short-term Debt
Short term debt, weighted average interest rate	4.60%
Maturities	397 days
Commercial paper	$ 1,000	$ 532

Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Weighted average interest rate of short-term debt outstanding calculated at point in time.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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