Quarterly Financial Data (unaudited) (Details) - USD ($)	1 Months Ended	3 Months Ended								12 Months Ended
	May 31, 2015	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Total revenue		$ 1,431,000,000	$ 1,380,000,000	$ 1,363,000,000	$ 1,331,000,000	$ 1,368,000,000	$ 1,313,000,000	$ 1,298,000,000	$ 1,275,000,000	$ 5,505,000,000	$ 5,254,000,000	$ 5,066,000,000
Cost of processing and services		561,000,000	551,000,000	547,000,000	553,000,000	553,000,000	541,000,000	542,000,000	542,000,000	2,212,000,000	2,178,000,000	2,164,000,000
Cost of product		200,000,000	186,000,000	180,000,000	181,000,000	210,000,000	172,000,000	168,000,000	181,000,000	747,000,000	731,000,000	717,000,000
Selling, general and administrative expenses		295,000,000	274,000,000	274,000,000	258,000,000	276,000,000	258,000,000	262,000,000	238,000,000	1,101,000,000	1,034,000,000	975,000,000
Total expenses		1,056,000,000	1,011,000,000	1,001,000,000	992,000,000	1,039,000,000	971,000,000	972,000,000	961,000,000	4,060,000,000	3,943,000,000	3,856,000,000
Operating income		375,000,000	369,000,000	362,000,000	339,000,000	329,000,000	342,000,000	326,000,000	314,000,000	1,445,000,000	1,311,000,000	1,210,000,000
Net income		215,000,000	214,000,000	212,000,000	289,000,000	189,000,000	218,000,000	127,000,000	178,000,000	930,000,000	712,000,000	754,000,000
Comprehensive income		$ 208,000,000	$ 219,000,000	$ 207,000,000	$ 294,000,000	$ 190,000,000	$ 209,000,000	$ 132,000,000	$ 170,000,000	$ 928,000,000	$ 701,000,000	$ 751,000,000
Net income per share - continuing operations
Basic (in dollars per share)		$ 0.99	$ 0.98	$ 0.95	$ 1.30	$ 0.83	$ 0.94	$ 0.54	$ 0.75	$ 4.22	$ 3.04	$ 3.04
Diluted (in dollars per share)		$ 0.98	$ 0.96	$ 0.94	$ 1.27	$ 0.81	$ 0.92	$ 0.53	$ 0.73	$ 4.15	$ 2.99	$ 2.99
Business Acquisition [Line Items]
Loss on early debt extinguishment	$ 85,000,000									$ 0	$ 85,000,000	$ 0
StoneRiver Group L.P. [Member]
Business Acquisition [Line Items]
Gain on sale of business interest					$ 146,000,000
Share of net transaction gains at unconsolidated affiliate, tax expense					$ 54,000,000						$ 13,000,000	$ 36,000,000