Other (Expense) Income, Net (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other Income and Expenses [Abstract]
Interest income	$ 0.1	$ 0.2
Net periodic postretirement benefit cost relating to Salaried VEBA	(1.2)	(1.6)
Realized gain on available for sale securities	1.5	1.2
Unrealized (loss) gain on equity securities	(0.6)	0.5
All other (expense) income, net	(0.6)
All other (expense) income, net		0.2
Other (expense) income, net	$ (0.8)	$ 0.5