Non-operating Income (Expense) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Nonoperating Income (Expense) [Abstract]
Interest Expense	$ (12.2)	$ (11.9)
Interest Costs Capitalized	0.0	3.4
Amortization of Debt Issuance Costs	(0.6)	(0.5)
Interest Income, Other	0.0	0.4
Interest Expense, Net	(12.8)	(8.6)
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	(1.9)	(1.3)
Other Nonoperating Income (Expense)	(1.9)	(1.3)
Nonoperating Income (Expense)	$ (14.7)	$ (9.9)