Revenue Recognition - Impacts of ASC 606 Adoption on Consolidated Statement of Income (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue:
Processing and services	$ 1,207	$ 1,186	$ 2,445	$ 2,364
Product	213	200	415	416
Total revenue	1,420	1,386	2,860	2,780
Expenses:
Cost of processing and services	560	573	1,128	1,143
Cost of product	179	175	370	357
Selling, general and administrative	320	276	625	553
(Gain) loss on sale of businesses	3	(10)	(229)	(10)
Total expenses	1,062	1,014	1,894	2,043
Operating income	358	372	966	737
Interest expense	(45)	(44)	(90)	(86)
Non-operating income	3	2	3	2
Income before income taxes and income from investments in unconsolidated affiliates	316	330	879	653
Income tax provision	(72)	(109)	(212)	(211)
Income from investments in unconsolidated affiliates	7	0	7	26
Net income	$ 251	$ 221	$ 674	$ 468
Net income per share – basic (in dollars per share)	$ 0.61	$ 0.52	$ 1.64	$ 1.10
Net income per share – diluted (in dollars per share)	$ 0.60	$ 0.51	$ 1.61	$ 1.08
Shares used in computing net income per share:
Basic (in shares)	408.4	423.6	410.7	426.3
Diluted (in shares)	416.4	432.5	419.0	435.5
Balances without adoption of ASC 606
Revenue:
Processing and services	$ 1,200		$ 2,416
Product	193		392
Total revenue	1,393		2,808
Expenses:
Cost of processing and services	561		1,130
Cost of product	181		370
Selling, general and administrative	317		624
(Gain) loss on sale of businesses	3		(232)
Total expenses	1,062		1,892
Operating income	331		916
Interest expense	(45)		(90)
Income before income taxes and income from investments in unconsolidated affiliates	289		829
Income tax provision	(68)		(201)
Income from investments in unconsolidated affiliates	7		7
Net income	$ 228		$ 635
Net income per share – basic (in dollars per share)	$ 0.56		$ 1.55
Net income per share – diluted (in dollars per share)	$ 0.55		$ 1.52
Shares used in computing net income per share:
Basic (in shares)	408.4		410.7
Diluted (in shares)	416.4		419.0
Adjustments | Accounting Standards Update 2014-09
Revenue:
Processing and services	$ (7)		$ (29)
Product	(20)		(23)
Total revenue	(27)		(52)
Expenses:
Cost of processing and services	1		2
Cost of product	2		0
Selling, general and administrative	(3)		(1)
(Gain) loss on sale of businesses	0		(3)
Total expenses	0		(2)
Operating income	(27)		(50)
Interest expense	0		0
Non-operating income	0		0
Income before income taxes and income from investments in unconsolidated affiliates	(27)		(50)
Income tax provision	4		11
Income from investments in unconsolidated affiliates	0		0
Net income	$ (23)		$ (39)
Net income per share – basic (in dollars per share)	$ (0.05)		$ (0.09)
Net income per share – diluted (in dollars per share)	$ (0.05)		$ (0.09)
Shares used in computing net income per share:
Basic (in shares)	0.0		0.0
Diluted (in shares)	0.0		0.0