Derivative Financial Instruments (Location And Fair Values Of Derivative Financial Instruments In Our Consolidated Statement Of Financial Position) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative assets fair value	$ 13	$ 43
Derivative liabilities fair value	78	10
Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	8	3
Derivative liabilities fair value	0	1
Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	8	3
Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities fair value	0	1
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	5	40
Derivative liabilities fair value	78	9
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	5	32
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member] | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value		8
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities fair value	36	2
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	0
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities fair value	$ 42	$ 7