CONTINGENCIES (Asset Retirement Obligations) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of year	$ 856	$ 731	$ 712
Liabilities incurred	9	5	12
Revisions to cash flow estimates	48	105	(17)
Accretion expense	58	54	52
Spending	(49)	(38)	(28)
Foreign currency translation adjustment	(1)	(1)	0
Balance at beginning of year	921	856	731
Less current portion	(31)	(69)	(46)
Long-term portion	890	787	685
New Mexico environmental and reclamation programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accrued reclamation and closure costs	424
Arizona environmental and reclamation programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accrued reclamation and closure costs	220
Chile environmental and reclamation programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accrued reclamation and closure costs	49
PT Freeport Indonesia environmental and reclamation programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Estimated years the mining activities are expected to continue (in years)	30
Accrued reclamation and closure costs	140
Long-term receivable held in long-term receivables for joint venture partner's share of reclamation and closure costs	14
Current cash balance of reclamation fund	15
Minimum cash fund balance, including interest, for reclamation activities upon mine closure	$ 100