Income Taxes (Tables)

9 Months Ended

Sep. 30, 2011

Table Text Block [Abstract]

Schedule of Income Taxes and Effective Tax Rate Table

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
millions except percentages	2011			2010			2011			2010
Income tax expense (benefit)	$	(1,468)		$	94		$	(762)		$	660
Effective tax rate		33	%		109	%		25	%		49	%