Strategic Investments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 24, 2018	Dec. 31, 2017
Schedule of Investments [Line Items]
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity	$ 335
Other Nonoperating Income (Expense)	(23)	$ (2)
Equity Method Investments	304			$ 209
Measurement Alternative Investments	84			81
Publicly-held Securities	12			15
Notes Receivable	43			47
Strategic Investments	$ 442			$ 353
Milipede [Member]
Schedule of Investments [Line Items]
Total consideration for share purchase			$ 90
Closing payment			325
Potential payments based on acheiving certain milestones			$ 125