Restructuring Plan (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring and other asset-related charges	$ 0	$ 8	$ 0	$ 10
Other exit costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other asset-related charges	0	3	0	4
inventory related charges [Member] | Cost of Services [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other asset-related charges	0	4	0	4
Asset related charges [Member] | Software and Software Development Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other asset-related charges	0	1	0	2
Discrete charge under ASC 712 [Member] | Severance and other employee related charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other asset-related charges	0	2	0	2
Severance charge under ASC 420 [Member] | Severance and other employee related charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other asset-related charges	$ 0	$ (2)	$ 0	$ (2)