SUPPLEMENTARY OIL AND GAS INFORMATION (UNAUDITED) SUPPLEMENTARY OIL AND GAS INFORMATION (UNAUDITED) (Schedule of Costs Not Subject to Amortization) (Details) $ in Billions	12 Months Ended
Dec. 31, 2016 USD ($)
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Reclassification to Well, Facilities, and Equipment Based on Determination of Proved Reserves	$ 4.9
Unproved properties [Member]
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Proceeds from sales	$ 1.6

The cash inflow associated with the amount received from the sale of a business segment or subsidiary or sale of an entity that is related to it but not strictly controlled during the period (for example, an unconsolidated subsidiary, affiliate, joint venture or equity method investment).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585

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