Libyan Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2011 boepd	Dec. 31, 2010 boepd	Sep. 30, 2011 Libyan Operations [Member]
Libyan Operations (Textual) [Abstract]
The net book value of the Corporation's assets in Libya			$ 400
The average production in Libya (in boepd)	14,000	23,000
The Corporation's proved reserves in Libya (in B.O.E)		167,000,000

The net quantity of proved reserves as of the balance sheet date. Proved oil reserves are the estimated quantities of crude oil and natural gas liquids which geological and engineering data demonstrate with reasonable certainty to be recoverable.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 932

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-10.(a)(2))

-URI http://asc.fasb.org/extlink&oid=6949603&loc=d3e511914-122862

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 19

-Paragraph 59F

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

-Name Regulation S-X (SX)

-Number 210

-Article 4

-Section 10

-Paragraph a

-Subparagraph 2

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 932

-SubTopic 235

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6821537&loc=d3e61831-109447

Name:	us-gaap_ProvedDevelopedAndUndevelopedReservesNet
Namespace Prefix:	us-gaap
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant