Acquisitions and Divestitures - Additional Information (Detail) (USD $)	1 Months Ended		12 Months Ended							12 Months Ended		12 Months Ended					12 Months Ended			12 Months Ended
	Apr. 30, 2012 acre	Jul. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Nov. 10, 2010	Aug. 10, 2010	Jul. 28, 2010	Jul. 20, 2010 Agreement	Dec. 31, 2012 Senior Unsecured Debt [Member]	Jan. 31, 2012 Yara International [Member]	Dec. 31, 2012 Burrup Holdings Limited (Yara Pilbara Holdings Pty Limited ) [Member]	Dec. 31, 2010 Gulf of Mexico, Devon [Member]	Aug. 10, 2010 BP's Oil And Gas Operations [Member]	Oct. 08, 2010 Western Canada Sedimentary Basin [Member]	Nov. 04, 2010 Western Desert, Egypt [Member]	Dec. 31, 2012 Bp Acquisitions [Member]	Dec. 31, 2010 Bp Acquisitions [Member]	Jul. 31, 2010 Bp Acquisitions [Member]	Dec. 31, 2010 Mariner Energy Inc [Member]	Nov. 10, 2010 Mariner Energy Inc [Member]
Business Acquisition [Line Items]
Cordillera's properties include approximately 312,000 net acres	312,000
Depositary shares in separate underwriting	6,272,667																25,300,000
Cash paid to seller			$ 2,700,000,000			$ 2,700,000,000															$ 1,700,000,000
Percentage of ownership											49.00%
Ownership percentage by other party												51.00%
Amount paid for acquisition		6,400,000,000									439,000,000			3,100,000,000	3,250,000,000	650,000,000			7,000,000,000
Acquisition of oil and gas properties													1,050,000,000
Number of acquisition agreements									3
Preferential purchase right							658,000,000
Revenues attributable to acquisition and merger													197,000,000					308,000,000		95,000,000
Direct expenses attributable to acquisitions			6,998,000,000										39,000,000					78,000,000		26,000,000
Debt before unamortized discount			12,411,000,000	7,262,000,000						1,500,000,000
Notes interest rate										5.10%
Debt instrument maturity date										Sep. 01, 2040
Public offerings of common stock underwritten			392,712,245	385,249,885				26,450,000										26,450,000		17,300,000
Depositary shares each representing		1/20th interest	1/20th interest
Mandatory convertibles preferred stock, Series D		6.00%	6.00%
Expenses in connection with Apache's merger, transition and acquisition activity			31,000,000	20,000,000	183,000,000
Business combination separation and other costs				20,000,000	114,000,000
Investment banking fees					42,000,000
Business combination other expenses					$ 27,000,000