Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Tax Provision
Provision (benefit) based on international income (loss) distribution			$ 27	$ 167
Adjustments to income tax provision:
Impairments with no tax benefit			113	9
Asset impairments			(5)	0
Finalization of prior year returns			0	4
Changes in valuation allowances			8	3
Accrual adjustments and other			1	(4)
Tax provision	$ 44	$ 70	$ 144	$ 179
Tax Rate
Provision (benefit) based on international income (loss) distribution (in hundredths)			20.50%	22.70%
Adjustments to income tax provision:
Asset impairments with no tax benefit (in hundredths)			86.00%	1.30%
Other asset impairments (in hundredths)			(3.80%)	(0.00%)
Finalization of prior year returns (in hundredths)			0.00%	0.50%
Changes in valuation allowances (in hundredths)			6.30%	0.40%
Accrual adjustments and other (in hundredths)			0.10%	(0.50%)
Tax provision (in hundredths)			109.10%	24.40%