Restructuring Programs - Certain Related Costs Incurred in Connection with Restructuring Programs (Details) $ in Millions		3 Months Ended	6 Months Ended
		Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($) employee
Restructuring Cost and Reserve [Line Items]
Related restructuring costs		$ 19	$ 77
Related restructuring costs, number of employees transferred | employee			2,200
Retention related severance/bonuses
Restructuring Cost and Reserve [Line Items]
Related restructuring costs	[1]	11	$ 20
Contractual severance costs
Restructuring Cost and Reserve [Line Items]
Related restructuring costs	[2]	0	38
Consulting and other costs
Restructuring Cost and Reserve [Line Items]
Related restructuring costs	[3]	$ 8	$ 19

[1] Includes retention related severance and bonuses for employees expected to continue working beyond their minimum notification period before termination.

[2] Reflects estimated severance costs we are contractually required to pay on employees transferred (approximately 2,200) as part of the shared service arrangement entered into with HCL Technologies.

[3] Represents professional support services associated with our business transformation initiatives.