Derivative Financial Instruments (Location And Amounts Of Pre-Tax Gains (Losses) On Derivative Financial Instruments Not Designated As Hedges) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member] | Foreign Currency Exchange Gains (Losses), net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of net gains (losses) on derivative instruments	$ 3	$ (3)	$ 6	$ 3