Goodwill and Intangible Assets - Goodwill and Changes in Carrying Amount of Goodwill by Operating Segment (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 685.7
Currency translation	(1.5)
Goodwill, Ending Balance	684.2
Specialty Engineered Materials
Goodwill [Roll Forward]
Goodwill, Beginning Balance	236.3
Currency translation	(1.0)
Goodwill, Ending Balance	235.3
Color, Additives and Inks
Goodwill [Roll Forward]
Goodwill, Beginning Balance	447.8
Currency translation	(0.5)
Goodwill, Ending Balance	447.3
PolyOne Distribution
Goodwill [Roll Forward]
Goodwill, Beginning Balance	1.6
Currency translation	0.0
Goodwill, Ending Balance	$ 1.6