Income Taxes (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) assessment	Dec. 31, 2016 USD ($)	Dec. 31, 2015
Income Taxes [Line Items]
Foreign earnings, as a percentage to total foreign earnings	59.00%	47.00%	51.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%	35.00%	35.00%
Effective Tax Rate Reconciliation, Tax Cuts and Jobs Act of 2017, Percent	21.00%
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Provisional Income Tax Expense (Benefit)	$ (379)
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Provisional Income Tax Expense (Benefit)	(528)
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Transition Tax for Accumulated Foreign Earnings, Provisional Income Tax Expense (Benefit)	149
Tax assets related to net operating loss carry-forwards related to certain international subsidiaries	254	$ 278
Deferred Tax Assets, Valuation Allowance	264	216
Tax assets related to net operating loss carry-forwards related to capital losses	64	57
Tax assets related to excess foreign tax credits	0	95
State tax attributes	78	62
Approximate undistributed earnings of foreign subsidiaries and affiliated corporate joint venture companies accounted for on the equity method	9,400
Accrued interest and penalties on unrecognized tax benefits	23	26
Positive impact on the tax expense if the total amount of unrecognized tax benefits were recognized by the Company at one time	56
Argentine Tax Authority [Member]
Income Taxes [Line Items]
Estimated additional tax assessment	203
Foreign [Member]
Income Taxes [Line Items]
Tax assets related to net operating loss carry-forwards related to certain international subsidiaries with no expiration date	151
Tax assets related to net operating loss carry-forwards related to certain international subsidiaries with expiration date	103
Valuation allowance recorded against tax assets related to net operating loss carry-forwards related to certain international subsidiaries	$ 134	126
Tax years 2004, 2006. and 2007 [Member] | Secretariat of the Federal Revenue Bureau of Brazil [Member]
Income Taxes [Line Items]
Number of separate tax assessments | assessment	3
Income Tax Examination, Estimate of Possible Loss	$ 474
Tax years 2004 to 2010 [Member] | Argentine Tax Authority [Member]
Income Taxes [Line Items]
Income Tax Examination, Estimate of Possible Loss	113
Tax Year 2009 [Member] | Tax and Customs Administration, Netherlands [Member]
Income Taxes [Line Items]
Income Tax Examination, Estimate of Possible Loss	108
Valuation Allowance, Other Tax Carryforward [Member]
Income Taxes [Line Items]
Deferred Tax Assets, Valuation Allowance	64	41
Valuation Allowance, Tax Credit Carryforward [Member]
Income Taxes [Line Items]
Deferred Tax Assets, Valuation Allowance		0
Valuation Allowance, Operating Loss Carryforwards [Member]
Income Taxes [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 65	$ 49