Income Taxes (Narrative) (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016 assessment	Sep. 30, 2015	Sep. 30, 2016 USD ($) assessment	Sep. 30, 2015
Income Tax Contingency [Line Items]
Effective income tax rate	28.30%	31.10%	27.70%	28.70%
Tax years 2004, 2006. and 2007 [Member] | Brazilian Federal Revenue Service [Member]
Income Tax Contingency [Line Items]
Number of separate tax assessments | assessment	3		3
Income Tax Examination, Estimate of Possible Loss			$ 455
Tax years 2004 to 2008 [Member] | Argentine Tax Authorities [Member]
Income Tax Contingency [Line Items]
Income Tax Examination, Estimate of Possible Loss			113
Tax years after 2008 [Member] | Argentine Tax Authorities [Member]
Income Tax Contingency [Line Items]
Income Tax Examination, Estimate of Possible Loss			159
Tax Year 2009 [Member] | Tax and Customs Administration, Netherlands [Member]
Income Tax Contingency [Line Items]
Income Tax Examination, Estimate of Possible Loss			$ 100