Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue		$ 3,786	$ 3,128	$ 11,020	$ 6,142
Selling, general and administrative		1,412	1,137	4,193	1,821
Gain on sale of businesses		(36)	0	(464)	(10)
Total expenses		3,244	2,754	9,684	5,011
Operating income		542	374	1,336	1,131
Interest expense, net		(174)	(164)	(535)	(279)
Debt financing activities		0	49	0	(47)
Other income (expense)		13	(3)	34	0
Income before income taxes and income from investments in unconsolidated affiliates		381	256	835	805
Income tax provision		(124)	(53)	(176)	(144)
Income from investments in unconsolidated affiliates		19	22	3	12
Net income		276	225	662	673
Less: net income attributable to noncontrolling interests and redeemable noncontrolling interests		12	27	4	27
Net income attributable to Fiserv, Inc.		$ 264	$ 198	$ 658	$ 646
Net income attributable to Fiserv, Inc. per share – basic (in dollars per share)		$ 0.39	$ 0.34	$ 0.98	$ 1.42
Net income attributable to Fiserv, Inc. per share – diluted (in dollars per share)		$ 0.39	$ 0.33	$ 0.96	$ 1.39
Shares used in computing net income attributable to Fiserv, Inc. per share:
Basic (in shares)		669.8	584.8	672.6	456.3
Diluted (in shares)		680.3	596.9	684.1	465.2
Processing and services
Revenue	[1]	$ 3,153	$ 2,608	$ 9,118	$ 5,229
Cost of goods sold and services		1,387	1,204	4,488	2,445
Product
Revenue		633	520	1,902	913
Cost of goods sold and services		$ 481	$ 413	$ 1,467	$ 755

[1] Includes processing and other fees charged to related party investments accounted for under the equity method of $62 million and $40 million for the three months ended September 30, 2020 and 2019, respectively, and $174 million and $58 million for the nine months ended September 30, 2020 and 2019, respectively (see Note 21).