Fair Value Measurements And Disclosure (Effect Of Derivatives On The Consolidated Statements Of Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on interest rate swaps	$ (1)	$ 0	$ (5)	$ 59
Gain (Loss) on long-term debt	1	0	5	(59)
Cross-currency swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) recognized in accumulated OCI	1,079	(487)	(2,091)	(1,082)
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) recognized in accumulated OCI	10	5	(1)	2
Foreign exchange contracts | Other income (expense) - net
Derivative Instruments, Gain (Loss) [Line Items]
Amount reclassified from accumulated OCI into income	(9)	6	4	16
Interest rate locks
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) recognized in accumulated OCI	0	(202)	(648)	(225)
Interest rate locks | Interest income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Amount reclassified from accumulated OCI into income	$ (25)	$ (15)	$ (59)	$ (47)