General Information (Unaudited) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Property, plant, equipment and mine development costs, net	$ 23,013,000,000		$ 23,013,000,000		$ 22,934,000,000
Deferred income taxes	3,839,000,000		3,839,000,000		3,649,000,000
Assets held for sale	626,000,000	$ 459,000,000	626,000,000	$ 459,000,000	508,000,000
Liabilities held for sale	273,000,000		273,000,000		323,000,000
Gain (Loss) on Disposition of Assets	70,000,000	$ 33,000,000	$ 126,000,000	$ 66,000,000
Freeport Cobalt [Member]
Gain (Loss) on Disposition of Assets	$ 50
Freeport Cobalt [Member] | FCX [Member]
Investment Owned, Percent of Net Assets	56.00%		56.00%
Increase (Decrease) in Assets Held-for-sale	$ 50,000,000
Restatement Adjustment [Member] | Kisanfu Exploration Project [Member]
Property, plant, equipment and mine development costs, net					90,000,000
Deferred income taxes					27,000,000
Assets held for sale					(90,000,000)
Liabilities held for sale					$ (27,000,000)