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Inventories (Narrative) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2011	Dec. 31, 2010
Inventories
Inventories provided by customers and suppliers	$ 2.9	$ 3.3
Decline in Uranium Spot Price Indicator	17.00%
Decline in Uranium Quantities Provided by Customers and Suppliers	4.00%

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Decline in Uranium Quantities Provided by Customers and Suppliers

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Decline in Uranium Spot Price Indicator

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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

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