Debt (Schedule Of Changes In Debt) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($)
Debt Instrument [Line Items]
Balance as of beginning-of-year	$ 6,367
Notes issued	1,289
Repayment of notes	(1,096)
Unamortized premiums (discounts)	(1)
Unamortized debt issuance costs	(6)
Unamortized adjustments from discontinued hedges	259
Fair value hedge on interest rate swap agreements	(87)
Balance as of end-of-period	6,736
3.40% notes Due 2031 [Member]
Debt Instrument [Line Items]
Notes issued	$ 500
Interest rate	3.40%
4.375% Notes Due 2050 [Member]
Debt Instrument [Line Items]
Notes issued	$ 300
Interest rate	4.375%
6.25% Senior Notes, Due 2020 [Member]
Debt Instrument [Line Items]
Repayment of notes	$ (300)
Interest rate	6.25%
4.85% Notes, Due 2021 [Member]
Debt Instrument [Line Items]
Repayment of notes	$ (296)
Interest rate	4.85%
LIBOR + 150 bps Term Loan Issued, Due 2022 [Member]
Debt Instrument [Line Items]
Notes issued	$ 500
Repayment of notes	$ (500)
LIBOR + 150 bps Term Loan Issued, Due 2022 [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Variable rate	1.50%