Capital Stock (Details Textuals)	1 Months Ended		12 Months Ended											12 Months Ended	1 Months Ended	12 Months Ended					12 Months Ended						12 Months Ended																	1 Months Ended	12 Months Ended				12 Months Ended
	Jul. 31, 2010 USD ($)	Aug. 31, 1998	Dec. 31, 2011 USD ($) UnitPrograms D Y	Dec. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)	Dec. 31, 2008 USD ($)	Dec. 31, 2011 CAD	May 05, 2011	Jul. 28, 2010 USD ($)	May 07, 2008 USD ($)	Feb. 29, 2008 USD ($)	Jun. 14, 2007 USD ($)	May 05, 2005 USD ($)	Dec. 31, 2011 Series A Preferred Stock [Member]	Aug. 31, 1998 Series B Preferred Stock USD ($)	Dec. 31, 2011 Series B Preferred Stock USD ($)	Dec. 31, 2009 Series B Preferred Stock USD ($)	Aug. 18, 2008 Non Employee Director [Member]	Dec. 31, 2010 Mariner Energy Inc [Member]	Nov. 10, 2010 Mariner Energy Inc [Member] USD ($)	Dec. 31, 2011 Stock Options [Member]	Dec. 31, 2011 Stock Appreciation Rights [Member] USD ($)	Dec. 31, 2010 Stock Appreciation Rights [Member] USD ($)	Dec. 31, 2009 Stock Appreciation Rights [Member] USD ($)	Dec. 31, 2004 Stock Appreciation Rights [Member] USD ($)	Dec. 31, 2003 Stock Appreciation Rights [Member] USD ($)	Dec. 31, 2004 Stock Appreciation Rights [Member] Non Executive Employee [Member]	Dec. 31, 2003 Stock Appreciation Rights [Member] Non Executive Employee [Member]	Dec. 31, 2011 Restricted Stock [Member] USD ($)	Dec. 31, 2010 Restricted Stock [Member] USD ($)	Dec. 31, 2009 Restricted Stock [Member] USD ($)	Dec. 31, 2011 Conditional Restricted Stock [Member] USD ($) Y	Dec. 31, 2010 Conditional Restricted Stock [Member] USD ($)	Dec. 31, 2011 Performance Program 2012 [Member]	Dec. 31, 2011 Performance Program 2011 [Member]	Dec. 31, 2011 Performance Program 2010 [Member]	Dec. 31, 2011 Share Appreciation Plan 2008 [Member] USD ($)	Dec. 31, 2010 Share Appreciation Plan 2008 [Member] USD ($)	Dec. 31, 2009 Share Appreciation Plan 2008 [Member]	Dec. 31, 2011 Share Appreciation Program 2008 [Member] USD ($)	Dec. 31, 2010 Share Appreciation Program 2008 [Member] USD ($)	Dec. 31, 2009 Share Appreciation Program 2008 [Member] USD ($)	Dec. 31, 2008 Share Appreciation Program 2008 [Member]	Mar. 31, 2011 Share Appreciation Plan 2005 [Member] USD ($)	Dec. 31, 2011 Share Appreciation Plan 2005 [Member] USD ($)	Dec. 31, 2010 Share Appreciation Plan 2005 [Member] USD ($)	Dec. 31, 2009 Share Appreciation Plan 2005 [Member] USD ($)	Dec. 31, 2008 Share Appreciation Plan 2005 [Member]	Dec. 31, 2011 Share Appreciation Program 2005 [Member]	Mar. 31, 2011 Share Appreciation Program 2005 [Member] USD ($)
Capital Stock (Textual) [Abstract]
Minimum Common Shares Issued To Convertible Preferred Stock Holders			11,600,000
Liquidation preference per share, depository share			$ 50
Stock-based compensation expenses, after tax			73,000,000	106,000,000	67,000,000																								49,000,000	47,000,000	24,000,000	8,000,000	4,000,000
Compensation expense			113,000,000	164,000,000	104,000,000																	76,000,000	73,000,000	37,000,000								12,000,000	7,000,000					27,000,000		8,000,000	49,000,000	23,000,000			1,000,000	6,000,000	6,000,000
Dividends, Common stock			$ 0.60	$ 0.60	$ 0.60
Shares Issued upon Conversion			1,265,000	1,265,000					1,265,000
Weighted average remaining contractual life for expected to vest			8.5
Weighted-average remaining life of unvested restricted stock units			1.2																													2.3
Period in which stock options expires after grant date																					10 years
Weighted average remaining contractual life for options outstanding			6.6
Period in which stock options become exercisable																					over a four-year period	Over four years
Aggregate intrinsic value of exercisable			58,000,000
Weighted average remaining contractual life for exercisable			5.1
Aggregate intrinsic value of expected to vest			4,000,000
Total compensation cost related to non-vested options not yet recognized			154,000,000				79,000,000																									91,000,000																		0
Intrinsic value of options exercised			50,000,000	62,000,000	39,000,000
Aggregate intrinsic value of options outstanding			62,000,000
Weighted-average grant-date fair value of options granted			$ 42.20	$ 34.12	$ 29.71
Cash received from exercise of options			56,000,000
Additional tax benefit for the amount of intrinsic value in excess of compensation cost			10,000,000
Settlement period for SARs			10 years
Weighted-average exercise price of SARs																									42.68	28.78
Issuance of stock appreciation rights to non-executive employees																											1,334,300	1,809,060
Weighted-average fair value of SARs outstanding																						$ 54.66
Nonvested shares outstanding																						475,130							2,115,000	2,210,000		1,019,000	523,000		539,526	479,890				1,372,000	1,485,000	2,592,000	2,814,000		0	400,000	1,103,000	2,001,000
Granted, Weighted Average Grant-Date Fair Value																													$ 124.16	$ 103.88	$ 84.30	$ 91.29								$ 71.28	$ 71.16	$ 79.61				$ 21.64	$ 24.29
Threshold days			10
Restricted stock units, vested (Percentage)																		50.00%
Total fair value of restricted stock awards vested																													85,000,000	69,000,000	34,000,000														9,000,000	18,000,000	21,000,000
Options and restricted stock, anti-dilutive			2,500,000	2,300,000	4,200,000
SARs exercised																						120,531
Consecutive trading days			30
Initial conditional restricted stock unit awards granted to eligible employees																																585,811		851,985	585,811	541,440
Restricted stock, capitalized			42,000,000	71,000,000	46,000,000																								28,000,000	28,000,000	12,000,000	5,000,000	3,000,000					14,000,000		5,000,000	27,000,000	13,000,000			1,000,000	3,000,000	3,000,000
Range of ultimate number of restricted stock units awarded																																			zero to 1,348,815 units	zero units to 1,199,725 units
Restricted stock units awarded																													887,851	1,143,989	1,119,936	586,000									25,000	93,000
Risk free interest rate			1.95%	2.31%	2.06%																																			2.98%					3.95%
Preferred stock, liquidation preference per share			$ 1,000	$ 1,000
Aggregate cash payments made to settle SARs																						12,000,000
Minimum units awarded based upon measurement																																			0	0
Maximum units awarded based upon measurement																																		2,129,962	1,348,815	1,199,725
Installments were awarded, if share price exceeded the interim goal											108	81
Redemption of right shares			$ 0.01
Target to increase share price by 2012										216
Target to increase share price by 2008													108
Target to increase share price by 2010										162
Target to increase share price by 2007													81
Shares Issuable Upon Vesting, Minimum Amount																																					0	0	1,035,640
Percentage of additional vest on succeeding anniversaries			25.00%
Preferred stock, par value
Shares issuable upon vesting, maximum amount																																					1,372,190	1,485,210	1,556,160
Expected volatility			34.47%	35.02%	38.73%																																			28.31%					28.02%
Total expense for share appreciation program																																					188,000,000							79,000,000
Expected dividend yields			0.47%	0.60%	0.73%																																			0.54%					0.57%
Purchase Price of series A Preferred stock per One - thousand share under rights Granted			100
Depositary shares in separate underwriting	25,300,000		25,300,000
Preferred stock, shares authorized			10,000,000	10,000,000
Price for exercising rights as above Percentage of market price of common share			50.00%
Series B Preferred Stock Description			Series A Preferred Stock In December 1995, the Company declared a dividend of one right (a Right) for each 2.31 shares (adjusted for subsequent stock dividends and a two-for-one stock split) of Apache common stock outstanding on January 31, 1996. Each full Right entitles the registered holder to purchase from the Company one ten-thousandth (1/10,000) of a share of Series A Preferred Stock at a price of $100 per one ten-thousandth of a share, subject to adjustment. The Rights are exercisable 10 calendar days following a public announcement that certain persons or groups have acquired 20 percent or more of the outstanding shares of Apache common stock or 10 business days following commencement of an offer for 30 percent or more of the outstanding shares of Apache’s outstanding common stock (flip in event); each Right will become exercisable for shares of Apache’s common stock at 50 percent of the then-market price of the common stock. If a 20-percent shareholder of Apache acquires Apache, by merger or otherwise, in a transaction where Apache does not survive or in which Apache’s common stock is changed or exchanged (flip over event), the Rights become exercisable for shares of the common stock of the Company acquiring Apache at 50 percent of the then-market price for Apache common stock. Any Rights that are or were beneficially owned by a person who has acquired 20 percent or more of the outstanding shares of Apache common stock and who engages in certain transactions or realizes the benefits of certain transactions with the Company will become void. If an offer to acquire all of the Company’s outstanding shares of common stock is determined to be fair by Apache’s board of directors, the transaction will not trigger a flip in event or a flip-over event. The Company may also redeem the Rights at $.01 per Right at any time until 10 business days after public announcement of a flip in event. These rights were originally scheduled to expire on January 31, 2006. Effective as of that date, the Rights were reset to one right per share of common stock and the expiration was extended to January 31, 2016. Unless the Rights have been previously redeemed, all shares of Apache common stock issued by the Company after January 31, 1996 will include Rights. Unless and until the Rights become exercisable, they will be transferred with and only with the shares of Apache common stock.
Percentage acquired by Apache shareholders on contingency			20.00%
Common stock, shares issued			385,249,885	383,668,297					26,450,000										17,300,000	17,280,000
Preferred stock, shares outstanding			1,265,000	1,265,000
Shares designated as Series A Junior Participating Preferred Stock			25,000
Underwritten public offering price per share	$ 88
Conversion of preferred stock to equity shares ratio, minimum			9.164
Underwritten public offering price value									2,300,000,000
Depositary shares each representing	1/20th interest		1/20th interest
Mandatory convertibles preferred stock, Series D	6.00%		6.00%	6.00%	5.68%
Conversion of preferred stock to equity shares ratio, maximum			11.364
Common stock, shares authorized			860,000,000	860,000,000				860,000,000
Net proceeds of sale of mandatory convertible preferred stock	1,200,000,000
Maximum Common Shares Issued To Convertible Preferred Stock			14,400,000
Number of conditional restricted stock unit programs			2
Additional shares due to award																																																	0
Class of Stock [Line Items]
Common stock, shares issued			385,249,885	383,668,297					26,450,000										17,300,000	17,280,000
Closing price per share of Mariner common stock in Stock Exchange																				$ 110.25
Total value of stock consideration related to Mariner Merger																				1,900,000,000
Number of common shares authorized for issuance								430,000,000
Increase in number of common shares authorized for issuance			860,000,000	860,000,000				860,000,000
Preferred stock, shares redeemed																100,000
Cumulative preferred stock interest rate	6.00%		6.00%	6.00%	5.68%
Dividend declared for Series A preferred stock														One right for each 2.31 shares Adjusted for susequent stock divident and two for one stock Split
Number of Days to exercise Right after Public announcement for entities acquiring more than 20% of outstanding shares														10 days
Number of days To exercise right after commencement of offer for 30% or more outstanding shares			10 days
Series B Preferred Stock shares																100,000
Series B Preferred Stock value				4,163,000,000											100,000,000
Depository shares		1,000,000
Series B Preferred Stock net proceeds															98,000,000
Series B Preferred Stock into depository conversion			one tenth of share
Mandatory Convertible Preferred Stock			1,265,000	1,265,000
Redemption per share																1000 per share plus 9.47 accrued and unpaid dividends
Cumulative cash dividend per share			$ 5.68													$ 9.47
Preferred dividends, shares outstanding			$ 306,000,000	$ 226,000,000	$ 209,000,000	$ 7,000,000											$ 7,000,000