Income Taxes (Components Of Net Deferred Income Tax Liability (Asset) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Deferred income tax liabilities [Abstract]
Property, plant and equipment basis differences	$ 2,751	$ 2,401
Intangibles	878	960
Deferred Revenue/Expense	14
Other, net	12	15
Gross deferred income tax liability	3,655	3,376
Deferred income tax assets [Abstract]
Pension liability	273	222
Tax operating loss carryforward	687	295
Employee benefits	255	262
Accrued expenses	44	50
Capital Lease Obligations	75
Tax Credits	30
Allowance for doubtful accounts	44	10
Other, net	2	48
Gross deferred income tax asset	1,410	887
Less: Valuation allowance	(271)	(177)
Net deferred income tax asset	1,139	710
Net deferred income tax liability	$ 2,516	$ 2,666