Inventories (Schedule of Inventories) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Inventory, Net [Abstract]
Separative work units inventory	$ 9.7	$ 20.1
Uranium inventory	65.4	109.6
Inventories	75.1	129.7
Separative work units owed to customers and suppliers	4.2	3.6
Uranium owed to customers and suppliers	60.0	99.4
Inventories owed to customers and suppliers	64.2	103.0
Separative work units net of liability	5.5	16.5
Uranium inventory net of liability	5.4	10.2
Inventories, net	$ 10.9	$ 26.7

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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6676-107765

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-SubTopic 10
-Section 35
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=68049868&loc=d3e3927-108312

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.6(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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