Regulatory Matters, Commitments, Contingencies And Environmental Liabilities Operating Leases, Rental Expense (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Rental expense(1)	[1]	$ 35	$ 31	$ 141	$ 90
Less: Sublease rental income		(3)	(9)	(15)	(27)
Rental expense, net		$ 32	$ 22	$ 126	$ 63

[1] (1) Includes contingent rentals totaling $9 million and $8 million for the three months ended September 30, 2015 and 2014 and $19 million and $17 million for the nine months ended September 30, 2015 and 2014, respectively.