Hedging Activities (Summary of Notional Amounts and Respective Fair Values of Derivative Financial Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Notional amount	$ 16,548	$ 16,104
Asset derivatives, fair value	183	249
Liability derivatives, fair value	(274)	(265)
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member]
Notional amount	826	2,123
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Asset derivatives, fair value	18	38
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Asset derivatives, fair value	14	37
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member] | Other Accrued Liabilities [Member]
Liability derivatives, fair value	(7)	(7)
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Liability derivatives, fair value	(1)	(4)
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member]
Notional amount	6,816	1,815
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Asset derivatives, fair value	28	5
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Asset derivatives, fair value	32	21
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Accrued Liabilities [Member]
Liability derivatives, fair value	(61)	(19)
Foreign Exchange Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Liability derivatives, fair value	(58)
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member]
Notional amount	8,906	12,166
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Asset derivatives, fair value	58	114
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Asset derivatives, fair value	33	34
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Accrued Liabilities [Member]
Liability derivatives, fair value	(75)	(74)
Translated Earnings Contracts [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Liability derivatives, fair value	$ (72)	$ (161)