Special Charges (Narrative)(Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2015
Actuarial (gain) loss from remeasurement, net					$ 29.6
Termination benefit costs		$ 8.7	$ 3.7	$ 4.5	13.6
DOE Share of Paducah Termination Benefit Costs			1.6	2.4	0.4
Payments for Restructuring			(13.4)	(13.6)	(7.3)
Restructuring Charges			$ 2.1	$ 2.1	$ 13.2
Cost of Sales [Member]
Actuarial (gain) loss from remeasurement, net	$ 48.8

DOE Share of Paducah Termination Benefit Costs

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Amount of gain (loss) related to change in benefit obligation resulting from changes in actuarial assumptions, for example, but not limited to, interest, mortality, employee turnover, salary, and temporary deviation from the substantive plan.

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Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

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