Hedging Activities (Effect on Consolidated Financial Statements) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Gain (loss) recognized in income	$ (93)	$ (121)	$ (448)
Not Designated as Hedging Instrument [Member]
Gain (loss) recognized in income	(71)	(137)	(475)
Foreign Exchange Contracts, Balance Sheet [Member] | Not Designated as Hedging Instrument [Member]
Gain (loss) recognized in income	27	(11)	4
Foreign Exchange Contracts, Loans [Member] | Not Designated as Hedging Instrument [Member]
Gain (loss) recognized in income	(5)	(5)	(31)
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member]
Gain (loss) recognized in income	$ (93)	$ (121)	$ (448)