(Schedule Of Interest Income And Interest Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Text Block Supplement [Abstract]
Interest expense	$ 600	$ 706	$ 734
Interest income	156	215	198
Capitalized interest costs	$ 31	$ 29	$ 30