Long-Term Liabilities (Narrative) (Details) (USD $)	6 Months Ended		6 Months Ended	0 Months Ended	6 Months Ended	0 Months Ended	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 EEUK [Member]	Apr. 30, 2013 EEUK [Member] Warrant One [Member]	Jun. 30, 2013 EEUK [Member] Warrant One [Member]	May 21, 2013 EEUK [Member] Warrant Two [Member]	Jun. 30, 2013 EEUK [Member] Warrant Two [Member]
Oil and Gas Delivery Commitments and Contracts [Line Items]
Monetary production payment	$ 125,000,000		$ 125,000,000
Grant of production payment termination amount			145,800,000
Montetary production payment, issuance costs			21,200,000
Fair value of issued warrants	$ 7,600,000
Shares issued for investment warrant				3,440,000		560,000
Exercise price of Investment Warrants				$ 3.014		$ 3.685
Warrants expiration date					Apr. 30, 2018		May 21, 2018