Strategic Investments (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Nov. 01, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Other Nonoperating Income (Expense)	$ (11)		$ (33)	$ (89)	$ (44)
Equity Method Investments	204			204			$ 265
Cost Method Investments	69			69			20
Available-for-sale Securities	32			32			20
Notes Receivable From Portfolio Companies	44			44			42
Investments	$ 349			$ 349			$ 347
investment impairment [Member]
Schedule of Investments [Line Items]
Other Nonoperating Income (Expense)		$ (53)
Subsequent Event [Member]
Schedule of Investments [Line Items]
potential up-front cash payment						$ 145
potential contingent payments to acquire investee						$ 130