Inventories (Schedule of Inventories) (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Inventory, Net [Abstract]
Separative work units inventory	$ 11.7	$ 5.0
Uranium inventory	394.2	156.6
Inventories	416.3	161.6
Separative work units owed to customers and suppliers	0.0	2.5
Uranium owed to customers and suppliers	238.9	13.7
Inventories owed to customers and suppliers	238.9	16.2
Separative work units net of liability	11.7	2.5
Uranium inventory net of liability	155.3	142.9
Conversion credits, net of liability	10.4	0.0
Conversion credits owed to customers and suppliers	0.0	0.0
Conversion credits, inventory	10.4	0.0
Inventories, net	$ 177.4	$ 145.4

Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 852
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
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-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
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-Publisher FASB
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(6))
-Publisher FASB
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