Acquisitions Narrative (Details) £ in Millions, $ in Millions		12 Months Ended
	Jul. 21, 2016 GBP (£)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) business	Dec. 31, 2014 USD ($) business
Business Acquisition [Line Items]
Number of businesses acquired | business			2	8
Business combinations achieved in stages with non-controlling interest acquired in previous years | business				2
Business Combination, Consideration Transferred				$ 575
Total consideration transferred			$ 609
VocaLink Holdings Limited [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired, Committed to Acquire	92.40%
Payments to Acquire Businesses, Committed to Acquire	£ 700	$ 860
Business Combination, Contingent Consideration, Liability, Committed to Acquire	£ 169	$ 210
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners, Committed to Acquire	7.60%
Noncontrolling Interest, Minimum Holding Period by Noncontrolling Owners, Committed to Acquire	3 years
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Goodwill acquired			$ 481	$ 509