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Related Party Transactions (Details) - USD ($) shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
	May 03, 2021	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	May 02, 2021
Equity investments
Related Party Transaction [Line Items]
Amounts due from unconsolidated merchant alliances		$ 37		$ 37		$ 36
Related Party Fees \| Equity investments
Related Party Transaction [Line Items]
Processing, administrative, and other fees		$ 50	$ 56	$ 100	$ 114
New Omaha Holdings
Related Party Transaction [Line Items]
Number of shares to be repurchased (in shares)	5.0
Share repurchase amount	$ 588
New Omaha Holdings \| Fiserv
Related Party Transaction [Line Items]
Ownership percentage by noncontrolling owner (less than at June 30, 2022)		5.00%		5.00%			13.00%
Merchant Alliances \| Related Party Fees \| Equity investments
Related Party Transaction [Line Items]
Processing, administrative, and other fees		$ 46	45	$ 93	90
Lending Solutions Business, Investment Services Business, and InvestCloud Holdings \| Related Party Fees \| Affiliated entities
Related Party Transaction [Line Items]
Processing, administrative, and other fees		$ 5	$ 13	$ 9	$ 26
Fiserv \| New Omaha Holdings
Related Party Transaction [Line Items]
Secondary public offering (in shares)	23.0