Other Property and Equipment Net Gains (Losses) on Sales of Fixed Assets Table (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Property, Plant and Equipment [Line Items]
Net (gains) losses on sales of fixed assets	$ 3	$ (23)
Natural Gas Compressors [Member]
Property, Plant and Equipment [Line Items]
Net (gains) losses on sales of fixed assets	0	(26)
Gathering and Processing Equipment [Member]
Property, Plant and Equipment [Line Items]
Net (gains) losses on sales of fixed assets	0	3
Exploration and Production Equipment [Member]
Property, Plant and Equipment [Line Items]
Net (gains) losses on sales of fixed assets	0	2
Land and Building [Member]
Property, Plant and Equipment [Line Items]
Net (gains) losses on sales of fixed assets	1	0
Other Assets [Member]
Property, Plant and Equipment [Line Items]
Net (gains) losses on sales of fixed assets	$ 2	$ (2)