Other Expense, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investment [Line Items]
Interest Income	$ 81	$ 48	$ 31
Interest Expense	(592)	(469)	(415)
Other Items, Net	(28)	(4)	(16)
Other Expense, Net	(539)	(425)	(400)
Fees Associated with Short-term Financing Commitments	32	22
Costs associated with entering into interest rate swap arrangements			7
Losses on Extinguishment of Debt	4	9	$ 12
Gain on Sale of Investments	$ 17	13
Joint Venture [Member]
Investment [Line Items]
Gain on Sale of Investments		8
Proceeds from Divestiture of Interest in Joint Venture		$ 65