Discontinued Operations (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended		32 Months Ended		1 Months Ended
Discontinued Operations (Narrative) (Details) (USD $)	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Pre-Tax [Member]	Jun. 30, 2012 After-Tax [Member]	Mar. 31, 2012 Angola [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds on divestiture of assets					$ 10,100,000,000	$ 8,000,000,000	$ 71,000,000
Revenues related to discontinued operations		0	0	43,000,000
Earnings (loss) from discontinued operations before income taxes	$ 0	$ 2,600,000,000	$ (16,000,000)	$ 2,600,000,000

Overall income (loss) from a disposal group that is classified as a component of the entity, before income tax, reported as a separate component of income before extraordinary items. Includes the following (before income tax): income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

+ References+ Details