Acquisitions (Unaudited) (Details) (USD $)	12 Months Ended	3 Months Ended			3 Months Ended			3 Months Ended		1 Months Ended	3 Months Ended		3 Months Ended				3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended
	Dec. 31, 2012	Jun. 30, 2013 Plains Exploration & Production Company [Member]	Dec. 31, 2012 Plains Exploration & Production Company [Member]	Dec. 05, 2012 Plains Exploration & Production Company [Member]	Jun. 30, 2013 McMoRan Exploration Co [Member]	Dec. 31, 2012 McMoRan Exploration Co [Member]	Dec. 05, 2012 McMoRan Exploration Co [Member]	Mar. 31, 2013 Kokkola Cobalt Chemicals Refinery [Member]	Mar. 29, 2013 Kokkola Cobalt Chemicals Refinery [Member]	Feb. 28, 2012 Senior Notes [Member]	Mar. 31, 2013 Senior Notes [Member]	Mar. 07, 2013 Senior Notes [Member]	Mar. 31, 2013 Bank Term Loan [Member]	Feb. 14, 2013 Bank Term Loan [Member]	Mar. 29, 2013 Lundin Mining Corporation [Member] Kokkola Cobalt Chemicals Refinery [Member]	Mar. 29, 2013 La Generale des Carrieres et des Mines [Member] Kokkola Cobalt Chemicals Refinery [Member]	Mar. 31, 2013 2.375% Senior Notes due March 2018 [Member] Senior Notes [Member]	Mar. 07, 2013 2.375% Senior Notes due March 2018 [Member] Senior Notes [Member]	Mar. 31, 2013 3.100% Senior Notes due March 2020 [Member] Senior Notes [Member]	Mar. 07, 2013 3.100% Senior Notes due March 2020 [Member] Senior Notes [Member]	Mar. 31, 2013 3.875% Senior Notes due March 2023 [Member] Senior Notes [Member]	Mar. 07, 2013 3.875% Senior Notes due March 2023 [Member] Senior Notes [Member]	Mar. 31, 2013 5.450% Senior Notes due March 2043 [Member] Senior Notes [Member]	Mar. 07, 2013 5.450% Senior Notes due March 2043 [Member] Senior Notes [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition								Mar. 29, 2013
Business Acquisition, Date of Acquisition Agreement	Dec. 05, 2012
Business Acquisition, Agreed-Upon Equity Interest Issued or Issuable, Number of Shares Per Share of Target Company			0.6531
Business Acquisition, Agreed-Upon Cost of Entity Acquired, Cash Paid Per Share				$ 25.00			$ 14.75
Business Acquistion, Agreed-Upon Cost of Entity Acquired, Cash Paid				$ 3,400,000,000			$ 3,400,000,000
Business Acquisition, Agreed-Upon Equity Interest Issued or Issuable, Number of Shares			91,000,000
Business Acqusition, Agree-Upon Cost of Entity Acquired, Cash Paid, Net of Pro-Forma Existing Interests Held							2,100,000,000
Buinsess Acquisition, Agreed-Upon Royalty Trust Units Issued or Issuable, Per Share of Target Company						1.15
Royalty Interest in Future Production							5.00%
Debt Instrument, Face Amount												6,500,000,000		4,000,000,000				1,500,000,000		1,000,000,000		2,000,000,000		2,000,000,000
Investment Owned, Percent of Net Assets									56.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners															24.00%	20.00%
Business Acquisition, Cost of Acquired Entity, Purchase Price									355,000,000
Business Acquisition, Cost of Acquired Entity, Cash Paid									34,000,000
Business Acquisition, Cash Consideration Funding Percentage									70.00%						30.00%
Business Acquisition, Contingent Consideration, Potential Cash Payment									110,000,000
Buisness Acquisition, Term of Contingent Consideration								3 years
Term of Debt Agreement													5 years				5 years		7 years		10 years		30 years
Proceeds from Issuance of Long-term Debt										$ 2,970,000,000	$ 6,400,000,000
Business Acquisition, Shareholder Meeting		May 20, 2013			Jun. 03, 2013