Income Taxes (Components Of Net Deferred Income Tax Liability (Asset) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Deferred income tax liabilities [Abstract]
Property, plant and equipment basis differences	$ 2,401	$ 2,451
Intangibles	960	1,076
Other, net	15	24
Gross deferred income tax liability	3,376	3,551
Deferred income tax assets [Abstract]
Pension liability	222	247
Tax operating loss carryforward	295	162
Employee benefits	262	304
Accrued expenses	50	55
Allowance for doubtful accounts	10	16
Other, net	48	39
Gross deferred income tax asset	887	823
Less: Valuation allowance	(177)	(140)
Net deferred income tax asset	710	683
Net deferred income tax liability	$ 2,666	$ 2,868