Goodwill and Identifiable Intangible Assets - Schedule of Goodwill (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,294.9
Foreign currency translation	(37.7)
Goodwill, ending balance	1,257.2
Performance Coatings
Goodwill [Roll Forward]
Goodwill, beginning balance	1,211.3
Foreign currency translation	(35.2)
Goodwill, ending balance	1,176.1
Mobility Coatings
Goodwill [Roll Forward]
Goodwill, beginning balance	83.6
Foreign currency translation	(2.5)
Goodwill, ending balance	$ 81.1