Income Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Taxes [Line Items]
Effective income tax rate	27.60%	28.70%	27.30%	28.30%
Brazilian Federal Revenue Service [Member]
Income Taxes [Line Items]
Number of separate tax assessments	3		3
Estimated Tax Assessment Including Penalties and Interest	$ 577		$ 577
Estimated Additional Tax Assessment	38		38
Argentine Tax Authorities [Member]
Income Taxes [Line Items]
Estimated Additional Tax Assessment	466		466
Estimated Tax Assessment Including Interest	$ 37		$ 37