Goodwill and Identifiable Intangible Assets - Schedule of Goodwill (Details) $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,294.9
Goodwill from acquisitions	372.8
Foreign currency translation	(47.9)
Goodwill, ending balance	1,619.8
Performance Coatings
Goodwill [Roll Forward]
Goodwill, beginning balance	1,211.3
Goodwill from acquisitions	372.8
Foreign currency translation	(45.2)
Goodwill, ending balance	1,538.9
Mobility Coatings
Goodwill [Roll Forward]
Goodwill, beginning balance	83.6
Goodwill from acquisitions	0.0
Foreign currency translation	(2.7)
Goodwill, ending balance	$ 80.9