Segment Information (Segment Reporting Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Revenue	$ 320.2	$ 293.8	$ 298.3
Gross Profit	112.1	117.9	114.5
LEU and Technical Solutions Segment
Segment Reporting Information [Line Items]
Revenue	320.2	293.8	298.3
Gross Profit	112.1	117.9	114.5
LEU and Technical Solutions Segment | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue	(5.0)	0.0	0.0
Gross Profit	(5.0)	0.0	0.0
Low Enriched Uranium Segment [Member]
Segment Reporting Information [Line Items]
Gross Profit	105.1	130.6	73.0
Low Enriched Uranium Segment [Member] | Consolidation, Eliminations
Segment Reporting Information [Line Items]
Gross Profit	107.1	130.6	73.0
Low Enriched Uranium Segment [Member] | Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue	5.0	0.0	0.0
Gross Profit	2.0	0.0	0.0
Technical Solutions Segment [Member]
Segment Reporting Information [Line Items]
Revenue	325.2	293.8	298.3
Gross Profit	7.0	(12.7)	41.5
Technical Solutions Segment [Member] | Consolidation, Eliminations
Segment Reporting Information [Line Items]
Gross Profit	10.0	(12.7)	41.5
Technical Solutions Segment [Member] | Intersegment Eliminations
Segment Reporting Information [Line Items]
Gross Profit	3.0
Product [Member]
Segment Reporting Information [Line Items]
Revenue	269.0	235.6	186.1
Product [Member] | Low Enriched Uranium Segment [Member]
Segment Reporting Information [Line Items]
Revenue	274.0	235.6	186.1
Separative Work Units [Member]
Segment Reporting Information [Line Items]
Revenue	208.2	196.2	163.3
Uranium [Member]
Segment Reporting Information [Line Items]
Revenue	60.8	39.4	22.8
Service [Member] | Technical Solutions Segment [Member]
Segment Reporting Information [Line Items]
Revenue	$ 51.2	$ 58.2	$ 112.2