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Debt and Equity (Details) - USD ($)		3 Months Ended
Debt and Equity (Details) - USD ($)	Mar. 27, 2019	Mar. 31, 2019	Mar. 31, 2018	May 02, 2019	Dec. 31, 2018
Total Debt [Abstract]
Total debt		$ 9,905,000,000			$ 11,141,000,000
Current portion of debt		(3,000,000)			(17,000,000)
Long-term debt, less current portion		9,902,000,000			11,124,000,000
Net gain (loss) on exchanges and early extinguishment of debt		(6,000,000)	$ (1,000,000)
Interest costs		$ 178,000,000	$ 176,000,000
Dividends declared per share of common stock (in dollars per share)	$ 0.05	$ 0.05	$ 0.05
Property, Plant and Equipment [Member]
Total Debt [Abstract]
Interest costs capitalized		$ 32,000,000	$ 25,000,000
Line of Credit [Member] \| Cerro Verde [Member]
Total Debt [Abstract]
Total debt		825,000,000			1,023,000,000
Line of Credit [Member] \| Letter of Credit [Member]
Total Debt [Abstract]
Letter of credit		13,000,000
Revolving credit facility, availability		1,500,000,000
Line of Credit [Member] \| Revolving Credit Facility [Member]
Total Debt [Abstract]
Debt		0
Revolving credit facility, availability		3,500,000,000
Senior Notes [Member]
Total Debt [Abstract]
Net gain (loss) on exchanges and early extinguishment of debt		(1,000,000)
Repayments of credit facility		200,000,000
Senior Notes [Member] \| 3.100% Senior Notes due March 2020 [Member]
Total Debt [Abstract]
Debt, principal	$ 1,000,000,000.0
Stated interest rate	3.10%
Net gain (loss) on exchanges and early extinguishment of debt		(5,000,000)
Senior Notes [Member] \| FCX [Member]
Total Debt [Abstract]
Total debt		8,595,000,000			9,594,000,000
Debentures [Member] \| Freeport McMoRan Corporation [Member]
Total Debt [Abstract]
Total debt		357,000,000			358,000,000
Other Debt, Including Capital Leases and Short Term Borrowings [Member]
Total Debt [Abstract]
Total debt		$ 128,000,000			$ 166,000,000
Subsequent Event [Member] \| Line of Credit [Member] \| Revolving Credit Facility [Member] \| Amended Credit Facility [Member]
Total Debt [Abstract]
Revolving credit facility, availability				$ 3,500,000,000
Subsequent Event [Member] \| Line of Credit [Member] \| Revolving Credit Facility [Member] \| Amended Credit Facility, Maturing April 20, 2024 [Member]
Total Debt [Abstract]
Revolving credit facility, availability				3,260,000,000
Subsequent Event [Member] \| Line of Credit [Member] \| Revolving Credit Facility [Member] \| Amended Credit Facility, Maturing April 20, 2023 [Member]
Total Debt [Abstract]
Revolving credit facility, availability				$ 240,000,000