Restructuring Expenses and Related Asset Impairments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Restructuring expenses and related asset impairments
Severance and other employee related costs	$ 0.5	$ 0.1	$ 5.4	$ 1.0
Asset impairments and other restructuring costs	0.6		1.0
Total restructuring expenses and related asset impairments	1.1	0.1	6.4	1.0
Restructuring Liability
Balance at beginning of the period			5.9
Accruals for severance and other employee related costs			5.4
Payments			(7.2)
Currency translation adjustments and other			(0.2)
Total restructuring liability	3.9		3.9
Grace Construction Products
Restructuring expenses and related asset impairments
Total restructuring expenses and related asset impairments	1.1
Corporate
Restructuring expenses and related asset impairments
Total restructuring expenses and related asset impairments	$ 1.1