Acquisitions And Divestitures (Details) (USD $) In Millions, except Per Share data	3 Months Ended	9 Months Ended
Sep. 30, 2010	Sep. 30, 2010
Proforma information for the Company as if the acquisition of properties
Revenues and Other	$ 3,447	$ 10,241
Net Income	812	2,542
Preferred Stock Dividends	19	57
Income Attributable to Common Stock	$ 793	$ 2,485
Net Income per Common Share - Basic	$ 2.08	$ 6.52
Net Income per Common Share - Diluted	$ 2.02	$ 6.41

Business Acquisition Pro Forma Net Income Loss Available To Common Stockholder Basic.

Name:	apa_BusinessAcquisitionProFormaNetIncomeLossAvailableToCommonStockholderBasic
Namespace Prefix:	apa
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Business Acquisition Pro Forma Preferred Stock Dividends.

+ Details

Name:	apa_BusinessAcquisitionProFormaPreferredStockDividends
Namespace Prefix:	apa
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Pro forma basic earnings per share or earnings per unit, which is commonly presented in initial public offerings based on the terms of the offering.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 11

-Section 02

-Paragraph b

-Subparagraph 7

+ Details

Name:	us-gaap_BasicEarningsPerShareProForma
Namespace Prefix:	us-gaap
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionProFormaInformationAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=6909870&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

+ References

+ Details

Name:	us-gaap_BusinessAcquisitionsProFormaRevenue
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Pro forma diluted earnings per share, which is commonly presented in initial public offerings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 11

-Section 02

-Paragraph b

-Subparagraph 7

+ Details

Name:	us-gaap_DilutedEarningsPerShareProForma
Namespace Prefix:	us-gaap
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration