Goodwill, Customer Relationships and Other Intangible Assets - Schedule of Goodwill and Other Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 11,141	$ 10,837
Customer Contracts And Relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	8,206	8,845
Accumulated amortization	300	126
Trade Names
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	119	126
Accumulated amortization	11	4
Patents and Developed Technology
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	271	252
Accumulated amortization	22	9
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	$ 390	$ 378