Income Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Taxes [Line Items]
Effective income tax rate	27.60%	32.20%	27.50%	30.30%
Brazilian Federal Revenue Service [Member]
Income Taxes [Line Items]
Number of separate tax assessments	3		3
Estimated Tax Assessment Including Penalties and Interest	$ 527		$ 527
Estimated Additional Tax Assessment	60		60
Argentine Tax Authorities [Member]
Income Taxes [Line Items]
Estimated Additional Tax Assessment	367		367
Estimated Tax Assessment Including Interest	$ 37		$ 37