Restructuring Expenses and Related Asset Impairments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Restructuring expenses and related asset impairments
Severance and other employee related costs	$ 1.5	$ 0.5	$ 5.7	$ 5.4
Asset impairments and other restructuring costs	2.1	0.6	3.0	1.0
Total restructuring expenses and related asset impairments	3.6	1.1	8.7	6.4
Restructuring Liability
Balance at beginning of the period			3.0
Accruals for severance and other employee related costs			6.0
Payments			(3.8)	(7.2)
Balance at end of the period	5.2		5.2
Grace Catalysts Technologies [Member]
Restructuring expenses and related asset impairments
Total restructuring expenses and related asset impairments	2.0
Grace Materials Technologies [Member]
Restructuring expenses and related asset impairments
Total restructuring expenses and related asset impairments	0.4
Grace Construction Products
Restructuring expenses and related asset impairments
Total restructuring expenses and related asset impairments	$ 1.2