Debt and Equity Transactions (Unaudited) (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Jul. 23, 2014	Apr. 30, 2014
Extinguishment of Debt [Line Items]
Long-term Debt, Gross	$ 20,700,000,000			$ 20,700,000,000
Liabilities, Fair Value Adjustment				218,000,000
Debt Instrument, Unamortized Discount (Premium), Net	20,000,000			20,000,000
Unamortized Debt Issuance Expense	111,000,000			111,000,000		$ 121,000,000
Net gain on early extinguishment of debt	0	$ 58,000,000		0	$ 63,000,000
Bank Term Loan [Member]
Extinguishment of Debt [Line Items]
Debt Instrument, Face Amount	4,000,000,000			4,000,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Two	205,000,000			205,000,000		650,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Three	272,000,000			272,000,000		200,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Four	1,000,000,000			1,000,000,000		$ 2,200,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Five	313,000,000			313,000,000
Long-term Debt, Maturities, Repayments of Principal after Year Five	1,300,000,000			1,300,000,000
Credit Facility [Domain] | Revolving Credit Facility [Member]
Extinguishment of Debt [Line Items]
Long-term Debt, Gross	458,000,000			458,000,000
Letters of Credit Issued, Amount	42,000,000			42,000,000
Line of Credit Facility, Remaining Borrowing Capacity	3,500,000,000			3,500,000,000
Line Of Credit Facility Remaining Borrowing Capacity Available For Letters Of Credit	1,500,000,000			1,500,000,000
Senior Notes [Member] | 6.625% Senior Notes due 2021 [Member]
Extinguishment of Debt [Line Items]
Extinguishment of Debt, Amount			$ 210,000,000
Debt Instrument, Interest Rate, Stated Percentage								6.625%
Net gain on early extinguishment of debt			$ 6,000,000
Cerro Verde [Member] | Credit Facility [Domain]
Extinguishment of Debt [Line Items]
Long-term Debt, Gross	1,500,000,000			1,500,000,000
Letters of Credit Issued, Amount	0			0
Line of Credit Facility, Remaining Borrowing Capacity	301,000,000			301,000,000
Line of Credit Facility, Maximum Borrowing Capacity	1,800,000,000			$ 1,800,000,000
Term of Debt Agreement				5 years
Cerro Verde [Member] | Shareholder Loan [Member]
Extinguishment of Debt [Line Items]
Long-term Debt, Gross	100,000,000			$ 100,000,000
Debt Instrument, Face Amount	800,000,000			$ 800,000,000
Debt Instrument, Description of Variable Rate Basis				London Interbank Offered Rate plus the current spread on Cerro Verde’s senior unsecured committed credit facility
Debt Instrument, Basis Spread on Variable Rate				0.50%
Debt Instrument, Maturity Date				Dec. 22, 2019
Related Party Transaction, Due from (to) Related Party	$ 57,000,000			$ 57,000,000
Freeport-McMoRan Oil & Gas [Member]
Extinguishment of Debt [Line Items]
Net gain on early extinguishment of debt		58,000,000			$ 64,000,000
Freeport-McMoRan Oil & Gas [Member] | Senior Notes [Member]
Extinguishment of Debt [Line Items]
Long-term Debt, Gross							$ 1,800,000,000
Liabilities, Fair Value Adjustment		167,000,000
Extinguishment of Debt, Amount		1,700,000,000
Net gain on early extinguishment of debt		58,000,000
Freeport-McMoRan Oil & Gas [Member] | Senior Notes [Member] | 6.125% Senior Notes due 2019 [Member]
Extinguishment of Debt [Line Items]
Extinguishment of Debt, Amount		263,000,000
Debt Instrument, Interest Rate, Stated Percentage							6.125%
Freeport-McMoRan Oil & Gas [Member] | Senior Notes [Member] | 6.5% Senior Notes due 2020 [Member]
Extinguishment of Debt [Line Items]
Extinguishment of Debt, Amount		525,000,000
Debt Instrument, Interest Rate, Stated Percentage							6.50%
Freeport-McMoRan Oil & Gas [Member] | Senior Notes [Member] | 6.75% Senior Notes due 2022 [Member]
Extinguishment of Debt [Line Items]
Extinguishment of Debt, Amount		350,000,000
Debt Instrument, Interest Rate, Stated Percentage							6.75%
Freeport-McMoRan Oil & Gas [Member] | Senior Notes [Member] | 6.875% Senior Notes due 2023 [Member]
Extinguishment of Debt [Line Items]
Extinguishment of Debt, Amount		$ 525,000,000
Debt Instrument, Interest Rate, Stated Percentage							6.875%