Long-Term Debt (Narrative) (Details) (USD $)	1 Months Ended	6 Months Ended																				0 Months Ended	6 Months Ended				6 Months Ended		6 Months Ended	0 Months Ended	6 Months Ended							6 Months Ended			6 Months Ended
	Jul. 28, 2011	Jul. 01, 2011	Jul. 28, 2011	Dec. 15, 2009	Dec. 15, 2009 Parent Company [Member] North America [Member] Subordinated Convertible Notes [Member]	Jul. 01, 2011 Parent Company [Member] North America [Member] Senior Floating Rate Notes [Member]	Dec. 31, 2010 Parent Company [Member] North America [Member] Senior Floating Rate Notes [Member]	Jul. 01, 2011 Parent Company [Member] North America [Member] Senior Floating Rate Notes Due 2015 [Member]	Jul. 01, 2011 Parent Company [Member] North America [Member] Subordinated Convertible Notes due 2029 [Member]	Dec. 31, 2010 Parent Company [Member] North America [Member] Subordinated Convertible Notes due 2029 [Member]	Nov. 30, 2006 Parent Company [Member] North America [Member] 0.875% Convertible Notes due 2013 [Member]	Jul. 01, 2011 Parent Company [Member] North America [Member] Senior Convertible Notes One Percent Due 2012 [Member]	Dec. 31, 2010 Parent Company [Member] North America [Member] Senior Convertible Notes One Percent Due 2012 [Member]	Dec. 15, 2009 Parent Company [Member] North America [Member] Senior Convertible Notes One Percent Due 2012 [Member]	Jul. 01, 2011 Parent Company [Member] North America [Member] 1.00% Senior Convertible Notes [Member]	Jul. 01, 2011 Parent Company [Member] North America [Member] 7.125% Senior Notes due 2017 [Member]	Dec. 31, 2010 Parent Company [Member] North America [Member] 7.125% Senior Notes due 2017 [Member]	Jul. 01, 2011 Minimum [Member] Eurodollar Loans [Member]	Jul. 01, 2011 Minimum [Member] Alternative Base Rate Loans [Member]	Jul. 01, 2011 Maximum [Member] Eurodollar Loans [Member]	Jul. 01, 2011 Maximum [Member] Alternative Base Rate Loans [Member]	Dec. 15, 2009 Subordinated Convertible Notes [Member]	Jul. 01, 2011 9.5% Senior Notes [Member]	Jul. 01, 2011 Senior Floating Rate Notes [Member]	Dec. 31, 2010 Senior Floating Rate Notes [Member]	Jul. 01, 2011 Senior Floating Rate Notes Due 2015 [Member]	Jul. 01, 2011 Subordinated Convertible Notes due 2029 [Member]	Dec. 31, 2010 Subordinated Convertible Notes due 2029 [Member]	Jul. 01, 2011 Senior Unsecured Notes [Member]	Nov. 30, 2006 0.875% Convertible Notes due 2013 [Member]	Jul. 01, 2011 0.875% Convertible Notes due 2013 [Member]	Jul. 01, 2011 1.00% Senior Convertible Notes due 2012 [Member]	Jul. 01, 2011 Senior Convertible Notes One Percent Due 2012 [Member]	Dec. 31, 2010 Senior Convertible Notes One Percent Due 2012 [Member]	Dec. 15, 2009 Senior Convertible Notes One Percent Due 2012 [Member]	Dec. 31, 2008 Senior Convertible Notes One Percent Due 2012 [Member]	Sep. 30, 2007 Senior Convertible Notes One Percent Due 2012 [Member]	Jul. 01, 2011 1.00% Senior Convertible Notes [Member]	Jul. 01, 2011 7.125% Senior Notes due 2017 [Member]	Dec. 31, 2010 7.125% Senior Notes due 2017 [Member]	Jul. 01, 2011 Amended Credit Facility [Member]
Maturities of long-term debt range, start		July 1, 2011
Maturities of long-term debt range, end		June 30, 2016
Maturities of long-term debt in 2011		$ 211,700,000
Maturities of long-term debt in 2012		77,800,000
Maturities of long-term debt in 2013		315,400,000
Maturities of long-term debt in 2014		8,200,000
Maturities of long-term debt in 2015		130,600,000
Maturities of long-term debt in 2016 and thereafter		375,400,000
Debt maturity date																										2015	November 2029				November 15, 2013		October 2012						April 2017
Debt principal amount					429,500,000	125,000,000	125,000,000	125,000,000	429,500,000	429,500,000	355,000,000	10,600,000	10,600,000	10,600,000	10,600,000	200,000,000	200,000,000												325,000,000								475,000,000
Interest rate on notes																							9.50%	2.60%	2.70%					0.875%	0.875%		1.00%		1.00%			1.00%	7.125%	7.125%
Fair value of debt																								123,400,000	114,400,000		599,400,000	521,000,000					10,000,000	9,700,000					205,000,000	197,500,000
Nonconvertible debt borrowing rate on debt instrument issuance date																						12.50%								7.35%	0.875%	1.00%				7.50%		1.00%	7.125%
Liability component of convertible notes																						162,900,000					164,500,000	163,900,000			230,900,000		9,800,000	9,500,000	389,700,000		348,200,000
Equity component of convertible notes																						266,600,000									124,100,000				74,700,000		126,800,000
Debt issuance fees and expenses																						14,500,000																			11,100,000
Amount of convertible notes tendered in exchange offer																																			464,400,000
Percentage of convertible notes tendered in exchange offer																																			97.80%
Debt instrument original issuance date																														November of 2006			September 2007
Purchase price of Phelps Dodge International Corporation funded by proceeds from notes																																	707,600,000
Weighted average conversion price per share	$ 43.22		$ 41.45																								$ 36.75				$ 50.36	$ 83.93
Common stock covered under note hedge																															7,048,880
Number of common stock shares required to be issued on exercise of warrants in equal installments on each of the fifteen consecutive business days beginning on and including February 13, 2014																															7,048,880
Weighted average outstanding share price excess of strike price																															$ 76.00
Premium over the closing price of the Company's shares of common stock included in strike price																															92.4
Payment of outstanding debt including accrued interest, under the company's amended credit facility																															87,800,000
Payments for cost of note hedges																															124,500,000
Payment of issuance costs and expenses of related to notes																													7,900,000		9,400,000							12,300,000
Proceeds from the issuance of the warrants																															80,400,000
Net increase in cash from receipt of the funds from convertible notes and related payments used for general																															213,700,000
Notes originally issued amount																													325,000,000
Payments for senior notes																							285,000,000
Payment for accrued interest related to senior notes																							9,300,000
Payment for tender fees and the inducement premium related to senior notes																							20,500,000
Net cash proceeds from notes used for general corporate purposes																													2,300,000
Borrowing capacity under credit facility																																									400,000,000
Sublimit for issuance of commercial and standby letters of credit																																									50,000,000
Sublimit for swingline loans under credit facility for issuance of commercial and standby letters of credit																																									20,000,000
LIBOR plus interest rate																		1.125%	0.00%	1.875%	0.625%
Proceeds from issuance of subordinated convertible notes transaction				$ 0