Debt And Related Expenses (Schedule Of Net Financing Cost Components) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Debt Disclosure [Abstract]
Interest based on debt outstanding	$ 157	$ 147	$ 481	$ 413
Early retirement of debt	84		84
Capitalized interest	(18)	(17)	(53)	(46)
Interest accretion on deferred installment payment - see Note 2	13		39
Other fees and expenses	9	8	24	16
Interest expense	245	138	575	383
Interest income	(2)	(2)	(5)	(5)
Net financing costs	$ 243	$ 136	$ 570	$ 378