Income Taxes (Tables)

9 Months Ended

Sep. 30, 2014

Income Tax Disclosure [Abstract]

Schedule of Income Taxes and Effective Tax Rate

The following summarizes income tax expense (benefit) and effective tax rates:

	Three Months Ended   September 30,						Nine Months Ended   September 30,
millions except percentages	2014			2013			2014			2013
Income tax expense (benefit)	$	627		$	240		$	1,719		$	1,263
Effective tax rate	35		%	52		%	340		%	43		%