Restructuring Expenses and Asset Impairments (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Restructuring Cost and Reserve [Line Items]
Repositioning expenses	$ 13,400,000	$ 0	$ 20,300,000	$ 0
Restructuring Expenses and Asset Impairments (In millions)
Restructuring expenses	4,400,000	2,000,000	13,900,000	2,700,000
Asset impairments	0	9,700,000	0	9,700,000
Total restructuring expenses and asset impairments	4,400,000	11,700,000	13,900,000	12,400,000
Restructuring Liability (In millions)
Balance, December 31, 2014			4,500,000
Restructuring expenses	4,400,000	$ 2,000,000	13,900,000	2,700,000
Payments			(8,500,000)	$ (3,400,000)
Currency translation adjustments and other			200,000
Balance, June 30, 2015	10,100,000		10,100,000
Grace Construction Products
Restructuring Expenses and Asset Impairments (In millions)
Restructuring expenses	3.0
Restructuring Liability (In millions)
Restructuring expenses	3.0
Grace Materials Technologies [Member]
Restructuring Expenses and Asset Impairments (In millions)
Restructuring expenses	0.3
Restructuring Liability (In millions)
Restructuring expenses	0.3
Grace Catalysts Technologies [Member]
Restructuring Expenses and Asset Impairments (In millions)
Restructuring expenses	0.7
Restructuring Liability (In millions)
Restructuring expenses	0.7
Corporate Segment [Member]
Restructuring Expenses and Asset Impairments (In millions)
Restructuring expenses	0.4
Restructuring Liability (In millions)
Restructuring expenses	0.4
Professional service fees [Member]
Restructuring Cost and Reserve [Line Items]
Repositioning expenses	9,700,000		16,100,000
Employee-related costs [Member]
Restructuring Cost and Reserve [Line Items]
Repositioning expenses	$ 3,700,000		$ 4,200,000