Hedging Activities (Effect on Consolidated Financial Statements) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Translated earnings contract (loss) gain, net	$ 219	$ (1,201)	$ (219)	$ (2,058)
Not Designated as Hedging Instrument [Member]
Translated earnings contract (loss) gain, net	204	(1,236)	(232)	(2,130)
Foreign Exchange Contracts, Balance Sheet [Member] | Foreign Currency Transaction and Hedge Gain (Loss), Net [Member] | Not Designated as Hedging Instrument [Member]
Translated earnings contract (loss) gain, net	(15)	(35)	(13)	(72)
Translated Earnings Contracts [Member] | Foreign Currency Transaction and Hedge Gain (Loss), Net [Member] | Not Designated as Hedging Instrument [Member]
Translated earnings contract (loss) gain, net	$ 219	$ (1,201)	$ (219)	$ (2,058)