Goodwill, Customer Relationships and Other Intangible Assets - Schedule of Goodwill and Other Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 11,132	$ 10,837
Customer Contracts And Relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	7,801	8,845
Accumulated amortization	659	126
Trade Names
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	106	126
Accumulated amortization	24	4
Patents and Developed Technology
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	295	252
Accumulated amortization	51	9
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	$ 401	$ 378