Equity Method Investments (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2011
Schedule of Equity Method Investments [Line Items]
Ownership interest in equity method investments (in hundredths)				50.00%
Equity Method Investments	$ 437	$ 367	$ 329
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Retained earnings related to undistributed earnings of equity method investees	105
AMPCO Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [Abstract]
Difference between the carrying value of an equity method investment and the underlying net assets of the investee	9
Balance Sheet Information
Current Assets	463	384
Noncurrent Assets	983	902
Current Liabilities	373	348
Noncurrent Liabilities	29	24
Statements of Operations Information
Operating Revenues	1,256	1,173	1,139
Operating Expenses	388	361	335
Operating Income	868	812	804
Other (Income), Net	(14)	(5)	(12)
Income Before Income Taxes	882	817	816
Income Tax Provision	212	200	201
Net Income	670	617	615
AMPCO [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest in equity method investments (in hundredths)	45.00%
Equity Method Investments	139	137
Alba Plant [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest in equity method investments (in hundredths)	28.00%
Equity Method Investments	95	93
CONE Gathering LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest in equity method investments (in hundredths)	50.00%
Equity Method Investments	184	121
Other Investees [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 19	$ 16