Goodwill and Other Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Changes in goodwill balances
Balance at the beginning of the period	$ 540.4	$ 402.4
Goodwill, Acquired During Period	17.8	140.6
Foreign currency translation	(1.3)	(2.6)
Balance at the end of the period	556.9	540.4
Grace Catalysts Technologies
Changes in goodwill balances
Balance at the beginning of the period	496.3	357.7
Goodwill, Acquired During Period	17.8	140.6
Foreign currency translation	(1.0)	(2.0)
Balance at the end of the period	513.1	496.3
Grace Materials Technologies
Changes in goodwill balances
Balance at the beginning of the period	44.1	44.7
Goodwill, Acquired During Period	0.0	0.0
Foreign currency translation	(0.3)	(0.6)
Balance at the end of the period	$ 43.8	$ 44.1