Other Operating Expenses - Summary of Net Pretax Charges Incurred by Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	$ 16	$ 24	$ 39	$ 45
Operating Segments | Global Business Solutions
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	6	2	15	5
Operating Segments | Global Financial Solutions
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	4	1	8	2
Operating Segments | Network & Security Solutions
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	1	0	3	2
Corporate
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	$ 5	$ 21	$ 13	$ 36