Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue		$ 4,756	$ 4,450	$ 9,303	$ 8,588
Selling, general and administrative		1,696	1,546	3,300	3,013
Net loss (gain) on sale of businesses and other assets		0	0	4	(147)
Total expenses		3,625	3,590	7,238	6,882
Operating income		1,131	860	2,065	1,706
Interest expense, net		(232)	(176)	(434)	(344)
Other expense, net		(26)	(66)	(46)	(70)
Income before income taxes and (loss) income from investments in unconsolidated affiliates		873	618	1,585	1,292
Income tax provision		(181)	(137)	(305)	(235)
(Loss) income from investments in unconsolidated affiliates		3	128	(9)	234
Net income		695	609	1,271	1,291
Less: net income attributable to noncontrolling interests and redeemable noncontrolling interests		12	11	25	24
Net income attributable to Fiserv, Inc.		$ 683	$ 598	$ 1,246	$ 1,267
Net income attributable to Fiserv, Inc. per share:
Basic (in dollars per share)		$ 1.11	$ 0.93	$ 2.01	$ 1.95
Diluted (in dollars per share)		$ 1.10	$ 0.92	$ 1.99	$ 1.94
Shares used in computing net income attributable to Fiserv, Inc. per share:
Basic (in shares)		615.4	645.2	621.2	648.0
Diluted (in shares)		619.2	650.8	625.3	654.0
Processing and services
Revenue	[1]	$ 3,924	$ 3,696	$ 7,597	$ 7,060
Cost of goods sold and services		1,351	1,502	2,756	2,938
Product
Revenue		832	754	1,706	1,528
Cost of goods sold and services		$ 578	$ 542	$ 1,178	$ 1,078

[1] Includes processing and other fees charged to related party investments accounted for under the equity method of $45 million and $50 million for the three months ended June 30, 2023 and 2022, respectively, and $91 million and $100 million for the six months ended June 30, 2023 and 2022, respectively (see Note 18).