Libyan Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2011	Dec. 31, 2010	Jun. 30, 2011 Libyan Operations [Member]
Libyan Operations [Line Items]
The net book value of the Corporation's assets in Libya			$ 400
Libyan Operation (Textuals) [Abstract]
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