Stockholder's Equity - Schedule of Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Stockholders' Equity Note [Abstract]
Net loss from pension and other postretirement benefit liabilities, net of income tax benefits of $31.6 million and $29.9 million, respectively	$ (94.3)	$ (89.6)
Unrealized foreign currency translation losses, net of income tax benefits of $0.3 and $0.3, respectively	(19.0)	(15.5)
AOCI	(113.3)	(105.1)
Foreign currency translation losses, tax benefit	0.3	0.3
Net loss from pension and other postretirement benefit liabilities, tax benefit	$ 31.6	$ 29.9