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Advanced Technology Costs and Other Income (Narrative) (Details) (USD $) In Millions, unless otherwise specified | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2013 | Jun. 30, 2012 | Jun. 30, 2013 | Jun. 30, 2012 | Dec. 31, 2012
Research and Development [Abstract] |  |  |  |  |
Maximum funding for RD&D Program |  |  | $ 350 |  |
RD&D Program Funding by DOE |  |  | 80.00% |  |
RD&D Program Funding by USEC |  |  | 20.00% |  |
Maximum RD&D Program Funding by DOE |  |  | 280 |  |
Maximum RD&D Program Funding by USEC |  |  | 70 |  |
RD&D Program Funding by DOE To Date |  |  | 227.7 |  |
RD&D Program Funding by DOE - Increment 1 |  |  | 87.7 |  |
RD&D Program Funding by DOE - Increment 2 |  |  | 45.7 |  |
RD&D Program Funding by DOE - Increment 3 |  |  | 44.4 |  |
RD&D Program Funding by DOE - Increment 4 |  |  | 49.9 |  |
RD&D Program Qualifying Expenditures To Date | 225.5 |  | 225.5 |  |
RD&D Program Qualifying Expenditures To Date - DOE Share | 180.4 |  | 180.4 |  |
RD&D Program Qualifying Expenditures To Date - DOE Share - Received | 156.2 |  | 156.2 |  |
RD&D Program Qualifying Expenditures To Date - DOE Share - Receivable | 24.2 | 4.4 | 24.2 | 4.4 |
RD&D Program Funding - DOE Advance | 21.7 |  | 21.7 |  | 2.4
RD&D Program Qualifying Expenditures | 50.9 |  | 110.4 |  |
RD&D Program Qualifying Expenditures - DOE Share | 40.7 | 10.0 | 88.3 | 10.0 |
RD&D Program Funding by DOE Remaining |  |  | 52.3 |  |
RD&D Program Funding by DOE Remaining - Government Requested |  |  | $ 48.0 |  |

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