Hedging Activities (Summary of Notional Amounts and Respective Fair Values of Derivative Financial Instruments) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Notional amount	$ 16,104	$ 14,911
Asset derivatives, fair value	249	148
Liability derivatives, fair value	(265)	(442)
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member]
Notional amount	2,123	391
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Asset derivatives, fair value	38	4
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Asset derivatives, fair value	37	2
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member] | Other Accrued Liabilities [Member]
Liability derivatives, fair value	(7)	(2)
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Liability derivatives, fair value	(4)
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member]
Notional amount	1,815	900
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Asset derivatives, fair value	5	5
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Asset derivatives, fair value	21
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Accrued Liabilities [Member]
Liability derivatives, fair value	(19)	(7)
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member]
Notional amount	12,166	13,620
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Asset derivatives, fair value	114	94
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Asset derivatives, fair value	34	43
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Accrued Liabilities [Member]
Liability derivatives, fair value	(74)	(47)
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Liability derivatives, fair value	$ (161)	$ (386)