Goodwill and Other Intangible Assets - Other Intangible Rollforward (Details) $ in Millions	9 Months Ended
	Sep. 30, 2017 USD ($)
Finite-lived Intangible Assets [Roll Forward]
Other intangible assets balance at December 31, 2016	$ 10,420
Acquisitions (divestitures), net	5
Foreign currency translation	60
Reclassification to held for sale	(214)
Other activity, net	(9)
Amortization of other intangible assets	(206)
Other intangible assets balance at September 30, 2017	$ 10,056