Asset Impairment, Restructuring and Other Special Charges - Summary of Activity in Reserves (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Restructuring Reserve [Roll Forward]
Balance at beginning of period	$ 20.9	$ 44.4
Charges	1.6	0.5
Reserve adjustments	(0.6)
Cash paid	(10.8)	(7.6)
Balance at end of period	11.1	37.3
Facility exit costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	5.4	9.3
Charges	0.6	0.0
Reserve adjustments	0.0
Cash paid	(1.0)	(0.3)
Balance at end of period	5.0	9.0
Severance
Restructuring Reserve [Roll Forward]
Balance at beginning of period	15.5	35.1
Charges	1.0	0.5
Reserve adjustments	(0.6)
Cash paid	(9.8)	(7.3)
Balance at end of period	$ 6.1	$ 28.3