Restructuring Costs - Summary of Changes in Restructuring Reserve (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	$ 69.3	$ 22.2
Expense	2.0	(1.1)
Paid/Utilized	(11.9)	(9.9)
Restructuring reserve, ending balance	59.4	11.2
Severance and benefits
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	68.9	21.6
Expense	0.2	(1.5)
Paid/Utilized	(10.1)	(9.5)
Restructuring reserve, ending balance	59.0	10.6
Plant closing and other
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	0.4	0.6
Expense	1.8	0.4
Paid/Utilized	(1.8)	(0.4)
Restructuring reserve, ending balance	$ 0.4	$ 0.6