Subsequent Events (Unaudited) (Details) - PT Freeport Indonesia [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Sep. 30, 2015	Jun. 30, 2015
Subsequent Event [Line Items]
Assurance Bond, Smelter Development			$ 115
Subsequent Event [Member]
Subsequent Event [Line Items]
Progressive Export Duty on Copper Concentrates, Percent		5.00%
Expiration Date, Memorandum of Understanding with Foreign Government		Jul. 25, 2015
Export Permit Renewal Term		6 months
Expiration Date, Export Permit	Jan. 28, 2016
Effective Date, Export Permit		Jul. 29, 2015
Stage 1 [Member]
Subsequent Event [Line Items]
Progressive Export Duty on Copper Concentrates, Percent			7.50%
Stage 2 [Member]
Subsequent Event [Line Items]
Progressive Export Duty on Copper Concentrates, Percent			5.00%
Smelter Development Progress, Percent			7.50%
Stage 3 [Member]
Subsequent Event [Line Items]
Progressive Export Duty on Copper Concentrates, Percent			0.00%
Smelter Development Progress, Percent			30.00%