Impairments of Fixed Assets and Other (Tables)

3 Months Ended

Mar. 31, 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 and the Prior Quarter is as follows:

	Three Months Ended March 31,
	2014		2013
	($ in millions)
Drilling rigs and equipment	$	20	$	—
Buildings and land	—		27
Total impairments of fixed assets and other	$	20	$	27