Derivative Financial Instruments (Notional Value Of Outstanding Cash Flow Hedge Contracts By Year Of Maturity And Net Unrealized (Loss) Gain Included In Accumulated Other Comprehensive Income) (Details) - Cash Flow Hedging [Member] - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Foreign Exchange Contract
Derivative [Line Items]
Net unrealized (losses) gains included in accumulated other comprehensive income (loss), net of taxes	$ (27)	$ 26
Designated as Hedging Instrument [Member] | Foreign Exchange Contract
Derivative [Line Items]
Derivative, Notional Amount	2,248	2,388
Designated as Hedging Instrument [Member] | Foreign Exchange Contract, Maturity 2020 [Member]
Derivative [Line Items]
Derivative, Notional Amount	773	1,505
Designated as Hedging Instrument [Member] | Foreign Exchange Contract, Maturity 2021 [Member]
Derivative [Line Items]
Derivative, Notional Amount	1,158	883
Designated as Hedging Instrument [Member] | Foreign Exchange Contract, Maturity 2022
Derivative [Line Items]
Derivative, Notional Amount	317	$ 0
Designated as Hedging Instrument [Member] | Foreign Exchange Option [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 75