Restructuring Expenses and Related Asset Impairments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring expenses and related asset impairments
Restructuring Charges	$ 22.8	$ 8.1	$ 12.5
Impairment of Long-Lived Assets to be Disposed of	0.1	14.3
Total restructuring expenses and asset impairments	22.9	22.4	12.5
Other than Temporary Impairment Losses, Investments		4.5
Repositioning expenses	64.3	0.0	0.0
Restructuring Liability
Balance at beginning of the period	4.5	4.4	3.0
Accruals for severance and other employee related costs	22.8	7.7	7.6
Payments	(16.4)	(7.9)	(6.4)
Currency translation adjustments and other	(0.2)	0.3	0.2
Total restructuring liability	10.7	4.5	$ 4.4
Grace Construction Products
Restructuring expenses and related asset impairments
Restructuring Charges	6.1	2.7
Impairment of Long-Lived Assets to be Disposed of		9.8
Grace Catalysts Technologies
Restructuring expenses and related asset impairments
Restructuring Charges	4.9	1.9
Grace Materials Technologies
Restructuring expenses and related asset impairments
Restructuring Charges	1.2	0.3
Corporate [Member]
Restructuring expenses and related asset impairments
Restructuring Charges	10.6	$ 3.2
Professional service fees [Member]
Restructuring expenses and related asset impairments
Repositioning expenses	49.8
Employee-related costs [Member]
Restructuring expenses and related asset impairments
Repositioning expenses	10.4
Asset impairments [Member]
Restructuring expenses and related asset impairments
Repositioning expenses	$ 4.1