Segment Information (Segment Reporting Information) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Revenue	$ 33.6	$ 104.7	$ 154.3	$ 154.0
Gross Profit	(0.8)	35.5	62.6	25.7
Low Enriched Uranium Segment [Member]
Segment Reporting Information [Line Items]
Gross Profit	(0.9)	33.4	61.0	25.1
Technical Solutions Segment [Member]
Segment Reporting Information [Line Items]
Gross Profit	0.1	2.1	1.6	0.6
Separative Work Units [Member]
Segment Reporting Information [Line Items]
Revenue	0.1	75.0	89.4	87.4
Uranium [Member]
Segment Reporting Information [Line Items]
Revenue	18.6	12.8	23.4	38.1
Product [Member]
Segment Reporting Information [Line Items]
Revenue	18.7	87.8	112.8	125.5
Service [Member]
Segment Reporting Information [Line Items]
Revenue	$ 14.9	$ 16.9	$ 41.5	$ 28.5

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

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-Name Accounting Standards Codification
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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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