Impairments of Fixed Assets and Other (Tables)

9 Months Ended

Sep. 30, 2014

Asset Impairment Charges [Abstract]

Details of Impairment of Long-Lived Assets Held and Used by Asset [Table Text Block]

A summary of our impairments of fixed assets by asset class and other charges for the Current Quarter, the Prior Quarter, the Current Period and the Prior Period is as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2014		2013		2014		2013
	($ in millions)
Natural gas compressors	$	11	$	—	$	11	$	—
Gathering systems and treating plants	—		21		10		22
Oilfield services equipment	—		24		23		27
Buildings and land	4		8		9		247
Other	—		32		22		47
Total impairments of fixed assets and other	$	15	$	85	$	75	$	343