Income Taxes (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($) assessment	Mar. 31, 2019
Income Tax Contingency [Line Items]
Effective income tax rate	(4.30%)	25.70%
Tax expense (credit) related to out of period discretes	$ (73)
Brazilian Federal Revenue Service [Member]
Income Tax Contingency [Line Items]
Number of separate tax assessments | assessment	3
Income tax assessment	$ 81
Income tax assessment - Interest and Penalties	239
Argentine Tax Authorities [Member]
Income Tax Contingency [Line Items]
Income tax assessment	13
Income tax assessment - Interest and Penalties	51
Estimated Additional Tax Assessment	40
Additional income tax assessment - Interest and Penalties	23
Tax and Customs Administration, Netherlands [Member]
Income Tax Contingency [Line Items]
Income tax assessment	89
Additional income tax assessment - Interest and Penalties	$ 34