Subsequent Event (Credit) (Details) (USD $)	1 Months Ended		12 Months Ended		12 Months Ended
	Jan. 31, 2013	May 31, 2012	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2012 [LetterOfCreditMember]	Dec. 31, 2012 [IssuanceOfDebtMember] [LetterOfCreditMember]	Dec. 31, 2012 [IssuanceOfDebtMember] [RevolvingCreditFacilityMember]	Dec. 31, 2012 [RepaymentOfDebtMember] [LetterOfCreditMember]	Jan. 10, 2013 [RepaymentOfDebtMember] [LetterOfCreditMember]
Subsequent Event [Line Items]
Subsequent Event Month			March 2013			January 2013
Subsequent Event, Description			In January 2013, we entered into the Procurement Agreement with an unaffiliated third party entity, which matures on July 9, 2014. The Procurement Agreement was entered into in connection with the unaffiliated third party’s entry into a credit support arrangement with a providing bank. Pursuant to this credit support arrangement, the third party pledged cash, contributed by one of our shareholders, to secure letters of credit in the amount of $33.0 million. The letters of credit secure decommissioning obligations in connection with certain of our U.K. license agreements.
Line of Credit Facility, Expiration Date			Dec. 31, 2013		Dec. 31, 2013	Jul. 09, 2014	Oct. 12, 2013	May 23, 2012
Line of Credit Facility, Extended Expiration Date			Jun. 30, 2014		Dec. 31, 2014		Jun. 30, 2014
Security Amount LOC Procurement Agreement			$ 33,000,000
Quarterly LOC Reimbursement Fee Percent	9.00%
Final LOC Termination Fee Percent	2.00%
Annual Payee Reimbursement Fee Percent	0.65%
Shares Issued For Investment Warrants	1,000,000	2,000,000
Investment Warrants, Exercise Price	$ 7.31	$ 10.50
First Reimbursement Agreement Termination Fee	3.8								3,800,000
Investment Warrants Expiration Date						Jan. 09, 2018
Line of Credit Facility, Maximum Borrowing Capacity				$ 125,000,000			$ 100,000,000