Restructuring - Summary of Net Pretax Charges Incurred by Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	$ (24)	$ (19)	$ (45)	$ (20)
Operating Segments | Global Business Solutions
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	(2)	(5)	(5)	(5)
Operating Segments | Global Financial Solutions
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	(1)	(4)	(2)	(4)
Operating Segments | Network & Security Solutions
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	0	0	(2)	0
Corporate
Net pretax benefits (charges), incurred by segment [Line items]
Restructuring, net	$ (21)	$ (10)	$ (36)	$ (11)