Revenue - Disaggregate Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue
Revenue	$ 2,084	$ 2,096	$ 6,256	$ 6,502
Recurring fees
Disaggregation of Revenue
Revenue	1,691	1,691	5,161	5,126
Non-recurring fees
Disaggregation of Revenue
Revenue	393	405	1,095	1,376
Processing and services
Disaggregation of Revenue
Revenue	1,457	1,473	4,494	4,474
License and software related
Disaggregation of Revenue
Revenue	347	327	1,000	983
Professional services
Disaggregation of Revenue
Revenue	193	240	564	889
Hardware and other
Disaggregation of Revenue
Revenue	87	56	198	156
North America
Disaggregation of Revenue
Revenue	1,568	1,531	4,687	4,755
All others
Disaggregation of Revenue
Revenue	516	565	1,569	1,747
Operating Segments
Disaggregation of Revenue
Revenue	2,084	2,096	6,256	6,502
Operating Segments \| IFS
Disaggregation of Revenue
Revenue	1,090	1,038	3,275	3,162
Operating Segments \| IFS \| Recurring fees
Disaggregation of Revenue
Revenue	959	911	2,901	2,763
Operating Segments \| IFS \| Non-recurring fees
Disaggregation of Revenue
Revenue	131	127	374	399
Operating Segments \| IFS \| Processing and services
Disaggregation of Revenue
Revenue	879	852	2,711	2,586
Operating Segments \| IFS \| License and software related
Disaggregation of Revenue
Revenue	92	94	269	289
Operating Segments \| IFS \| Professional services
Disaggregation of Revenue
Revenue	40	41	120	146
Operating Segments \| IFS \| Hardware and other
Disaggregation of Revenue
Revenue	79	51	175	141
Operating Segments \| IFS \| North America
Disaggregation of Revenue
Revenue	1,046	997	3,143	3,044
Operating Segments \| IFS \| All others
Disaggregation of Revenue
Revenue	44	41	132	118
Operating Segments \| GFS
Disaggregation of Revenue
Revenue	916	975	2,742	3,064
Operating Segments \| GFS \| Recurring fees
Disaggregation of Revenue
Revenue	663	703	2,042	2,112
Operating Segments \| GFS \| Non-recurring fees
Disaggregation of Revenue
Revenue	253	272	700	952
Operating Segments \| GFS \| Processing and services
Disaggregation of Revenue
Revenue	509	545	1,566	1,645
Operating Segments \| GFS \| License and software related
Disaggregation of Revenue
Revenue	255	232	730	680
Operating Segments \| GFS \| Professional services
Disaggregation of Revenue
Revenue	151	197	438	733
Operating Segments \| GFS \| Hardware and other
Disaggregation of Revenue
Revenue	1	1	8	6
Operating Segments \| GFS \| North America
Disaggregation of Revenue
Revenue	456	464	1,343	1,473
Operating Segments \| GFS \| All others
Disaggregation of Revenue
Revenue	460	511	1,399	1,591
Corporate and Other
Disaggregation of Revenue
Revenue	78	83	239	276
Corporate and Other \| Recurring fees
Disaggregation of Revenue
Revenue	69	77	218	251
Corporate and Other \| Non-recurring fees
Disaggregation of Revenue
Revenue	9	6	21	25
Corporate and Other \| Processing and services
Disaggregation of Revenue
Revenue	69	76	217	243
Corporate and Other \| License and software related
Disaggregation of Revenue
Revenue	0	1	1	14
Corporate and Other \| Professional services
Disaggregation of Revenue
Revenue	2	2	6	10
Corporate and Other \| Hardware and other
Disaggregation of Revenue
Revenue	7	4	15	9
Corporate and Other \| North America
Disaggregation of Revenue
Revenue	66	70	201	238
Corporate and Other \| All others
Disaggregation of Revenue
Revenue	$ 12	$ 13	$ 38	$ 38