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Inventories (Narrative) (Details) (USD $) In Millions, unless otherwise specified | 3 Months Ended |
--- | --- | ---
Mar. 31, 2014 | Dec. 31, 2013
Inventory, Net [Abstract] |  |
Inventories provided by customers and suppliers | $ 954 | $ 1,300
Decline in Uranium Spot Price Indicator | 3.00% |
Decline in Uranium Quantities Provided by Customers and Suppliers | 23.00% |

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- Details
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Period Type: | duration

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- Definition Decline in Uranium Quantities Provided by Customers and Suppliers + References No definition available. + Details
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- Definition Decline in Uranium Spot Price Indicator + References No definition available. + Details
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Namespace Prefix: | usu_
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- Definition Uranium held by USEC to which title was held by customers and suppliers and for which no assets or liabilities were recorded on the balance sheet + References No definition available. + Details
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