Income Taxes (Tables)

3 Months Ended

Mar. 31, 2016

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   March 31,
millions except percentages	2016			2015
Income tax expense (benefit)	$	(383	)	$	(1,392	)
Income (loss) before income taxes	(1,381		)	(4,628		)
Effective tax rate	28		%	30		%