Goodwill and Other Intangible Assets, Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Goodwill [Roll Forward]
Balance Beginning	$ 907.5	$ 808.5
Change in goodwill relating to [Abstract]
Acquisition of Normerica/Concept Pet	9.2	104.5
Foreign exchange translation	(1.9)	(5.5)
Total changes	7.3	99.0
Balance Ending	914.8	907.5
Performance Materials [Member]
Goodwill [Roll Forward]
Balance Beginning	853.0	752.4
Change in goodwill relating to [Abstract]
Acquisition of Normerica/Concept Pet	9.2	104.5
Foreign exchange translation	(0.5)	(3.9)
Total changes	8.7	100.6
Balance Ending	861.7	853.0
Specialty Minerals [Member]
Goodwill [Roll Forward]
Balance Beginning	12.6	12.7
Change in goodwill relating to [Abstract]
Acquisition of Normerica/Concept Pet	0.0	0.0
Foreign exchange translation	(0.8)	(0.1)
Total changes	(0.8)	(0.1)
Balance Ending	11.8	12.6
Refractories [Member]
Goodwill [Roll Forward]
Balance Beginning	41.9	43.4
Change in goodwill relating to [Abstract]
Acquisition of Normerica/Concept Pet	0.0	0.0
Foreign exchange translation	(0.6)	(1.5)
Total changes	(0.6)	(1.5)
Balance Ending	$ 41.3	$ 41.9