Debt (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Debt for Apache and subsidiaries
Debt before unamortized discount	$ 7,262	$ 8,190
Unamortized discount	(46)	(49)
Total debt	7,216	8,141
Current maturities	(431)	(46)
Long-term debt	6,785	8,095
United States [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	6,580	7,509
Money Market Lines of Credit [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	0	16
Commercial Paper [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	0	913
6.25% notes due 2012 [Member}
Debt for Apache and subsidiaries
Debt before unamortized discount	400	400
5.25% notes due 2013 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	500	500
6.0% notes due 2013 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	400	400
5.625% notes due 2017 [member]
Debt for Apache and subsidiaries
Debt before unamortized discount	500	500
6.9% notes due 2018 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	400	400
7.0% notes due 2018 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	150	150
7.625% notes due 2019 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	150	150
3.625% notes due 2021 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	500	500
7.7% notes due 2026 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	100	100
7.95% notes due 2026 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	180	180
6.0% notes due 2037 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	1,000	1,000
5.1% notes due 2040 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	1,500	1,500
5.25% notes due 2042 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	500	500
7.375% debentures due 2047 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	150	150
7.625% debentures due 2096 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	150	150
Subsidiary and other obligations [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	682	681
Argentina overdraft lines of credit [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	31	30
Notes due in 2016 and 2017 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	1	1
Apache Finance Canada 4.375% notes due 2015 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	350	350
Apache Finance Canada 7.75% notes due 2029 [Member]
Debt for Apache and subsidiaries
Debt before unamortized discount	$ 300	$ 300

Debt current and long term.

No definition available.

Name:	apa_DebtCurrentAndLongTerm
Namespace Prefix:	apa_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of the sum of short-term debt and current maturities of long-term debt and capital lease obligations, which are due within one year (or one business cycle if longer).

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19,20)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

+ References

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 16, 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

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

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number APB14-1

-Paragraph 31

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 16, 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentUnamortizedDiscount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_LongTermDebtAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year (current maturities) or the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LongTermDebtNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant