Inventories (Schedule of Inventories) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Inventory, Net [Abstract]
Separative work units inventory	$ 18.4	$ 20.1
Uranium inventory	123.3	109.6
Inventories	141.7	129.7
Separative work units owed to customers and suppliers	0.5	3.6
Uranium owed to customers and suppliers	58.5	99.4
Inventories owed to customers and suppliers	59.0	103.0
Separative work units net of liability	17.9	16.5
Uranium inventory net of liability	64.8	10.2
Inventories, net	$ 82.7	$ 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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