For a disposal group that is a component of the entity (discontinued operation), in the period in which the operations are initially classified as discontinued, the amounts of intercompany costs that were previously eliminated in consolidation for periods before the disposal transaction (in situations where revenue and cost producing activities with the disposed component will continue after disposal).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 20

-Section 50

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1518-107760

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

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 03-13

-Paragraph 17

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

Name:	us-gaap_DiscontinuedOperationIntercompanyAmountsWithDiscontinuedOperationBeforeDisposalTransactionCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Segment Disclosures (Details Textual) (USD $)	12 Months Ended
Segment Disclosures (Details Textual) (USD $)	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Access Midstream Partners [Member]	Dec. 20, 2012 Access Midstream Partners [Member]	Dec. 20, 2012 Access Midstream Ventures Llc [Member] General Partner [Member]	Dec. 20, 2012 Access Midstream Partners Lp [Member] Limited Partner [Member]
Segment Disclosures [Abstract]
Revenues from former exploration and production business now shown as external	$ 310,000,000	$ 264,000,000
Costs attributable to former exploration and production business now shown as external	845,000,000	797,000,000
Segment Reporting Information [Line Items]
Equity Method Investment, Ownership Percentage			25.00%	25.00%	50.00%	24.00%
Equity Method Investment, Aggregate Cost				$ 2,190,000,000