Segment Information (Segment Reporting Information) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Revenue	$ 75.7	$ 10.6	$ 120.7	$ 49.3
Gross Profit	43.8	(4.3)	63.4	(9.8)
Low Enriched Uranium Segment [Member]
Segment Reporting Information [Line Items]
Gross Profit	44.5	(5.1)	61.9	(8.3)
Technical Solutions Segment [Member]
Segment Reporting Information [Line Items]
Gross Profit	(0.7)	0.8	1.5	(1.5)
Separative Work Units [Member]
Segment Reporting Information [Line Items]
Revenue	58.6	0.0	89.3	12.4
Uranium [Member]
Segment Reporting Information [Line Items]
Revenue	4.8	2.6	4.8	25.3
Product [Member]
Segment Reporting Information [Line Items]
Revenue	63.4	2.6	94.1	37.7
Service [Member]
Segment Reporting Information [Line Items]
Revenue	$ 12.3	$ 8.0	$ 26.6	$ 11.6

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

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-Publisher FASB
-Name Accounting Standards Codification
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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
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