General Information (Unaudited) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Property, plant, equipment and mine development costs, net	$ 22,923	$ 22,934
Deferred income taxes	3,702	3,649
Assets held for sale	625	508	$ 373
Liabilities held for sale	$ 353	323
Restatement Adjustment [Member] | Kisanfu Exploration Project [Member]
Property, plant, equipment and mine development costs, net		90
Deferred income taxes		27
Assets held for sale		(90)
Liabilities held for sale		$ (27)