Goodwill, Customer Relationships and Other Intangible Assets - Schedule of Goodwill and Other Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 7,412	$ 11,119
Customer Contracts And Relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	7,398	7,567
Accumulated amortization	1,006	833
Trade Names
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	93	100
Accumulated amortization	37	30
Patents and Developed Technology
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	329	310
Accumulated amortization	84	67
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	$ 422	$ 410