Segment Information Schedule Of Entity Wide Revenue By Major Customers (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Customer A [Member] | Low Enriched Uranium Segment [Member]
Revenue, Major Customer [Line Items]
Revenue	$ 18.2	$ 11.3	$ 28.5	$ 32.4
Customer A [Member] | Technical Solutions Segment [Member]
Revenue, Major Customer [Line Items]
Revenue	$ 56.5	13.5	$ 87.7	33.4
Customer B [Member] | Low Enriched Uranium Segment [Member]
Revenue, Major Customer [Line Items]
Revenue		$ 7.4		23.4
Customer C [Member] | Low Enriched Uranium Segment [Member]
Revenue, Major Customer [Line Items]
Revenue				$ 17.9