Development Contracts - Additional Information (Details) (USD $)
1 Months Ended 3 Months Ended 9 Months Ended 78 Months Ended 1 Months Ended 73 Months Ended 78 Months Ended 80 Months Ended 1 Months Ended 73 Months Ended 80 Months Ended 1 Months Ended
Feb. 28, 2007
Sep. 30, 2012
Sep. 30, 2011
Sep. 30, 2012
Sep. 30, 2011
Sep. 30, 2012
Dec. 31, 2011
Dec. 31, 2009
Award 1
Oct. 31, 2007
Award 1
Apr. 16, 2012
Unreimbursed Amount under Awards 1 and 2
Sep. 30, 2012
Unreimbursed Amount under Awards 1 and 2
Dec. 10, 2012
Unreimbursed Amount under Awards 1 and 2
Feb. 28, 2007
Department Of Energy
Apr. 16, 2012
Reimbursements received under Department of Energy Awards 1 and 2
Dec. 10, 2012
Reimbursements received under Department of Energy Awards 1 and 2
Dec. 31, 2009
Fulton Project
Oct. 31, 2009
Fulton Project
Dec. 31, 2009
Fulton Project
Award 2
Research And Development Arrangement Contract To Perform For Others [Line Items]                                    
Grant awarded by Department of Energy $ 40,000,000             $ 7,000,000 $ 10,000,000         $ 9,243,984 $ 10,149,000 $ 88,000,000 $ 3,841,000 $ 81,000,000
Award, cost sharing percentage 60.00%                       40.00%          
Total grant available to Entity under awards           87,560,000                        
Project development   129,000 158,000 420,000 429,000 14,883,000       78,316,000 0 77,411,000            
Overpayment from the cumulative reimbursements of DOE grants under Award 1   $ 354,000   $ 354,000   $ 354,000 $ 366,000