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Commitment and Contingencies (Details) (USD $)	9 Months Ended
	Sep. 30, 2011	Dec. 31, 2010
Commitments and Contingencies
ACP spending reduction in October 2011	30.00%
Approximate ACP workers receiving WARN notices	450.0
Upper range of potential ACP asset impairment expense	$ 1,300,000,000
Estimated maximum potential severance liability	1,000,000	25,000,000
Estimated maximum potential severance liability, DOE share		$ 18,500,000

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ACP Spending Reduction in October 2011

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Approximate number of ACP workers receiving WARN notices

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Maximum potential severance liability

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Maximum potential severance liability shared by others (DOE)

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Upper range of potential ACP asset impairment expense

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