Income Taxes (Details 2) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended
	Nov. 30, 2011	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions	$ 10.6	$ 9.6	$ 0.8	[1],[2]	$ 17.8	[3],[4]
Tax Credit Carryforwards Before Valuation Allowances on Federal Tax Credits		65.2
Valuation Allowance, Amount		4.4
Deferred Tax Assets, Net of Valuation Allowance, Expected to Use		52.4
Deferred Tax Assets, Tax Credit Carryforwards With No Expiration		8.4
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation		57.7
Deferred Tax Assets, Tax Credit Carryforwards		16.9	2.4
Period permitted to carryforward NOLs under federal income tax law (in years)		20 years
Unrepatriated Foreign Earnings
Undistributed foreign earnings		1,126.5
Unrecorded deferred tax liability		149.7
Repatriation of cash from foreign entities		25.9	22.1		30.1
Amount of Uncertain Tax Position Reclassified to Income Taxes Payable					$ 6.7

[1] In 2012, $1.0 million of uncertain tax positions representing withholding taxes due were paid as a result of the completion of Grace's Canadian audit for the years 2002, 2003, and 2004.

[2] In 2013, $9.6 million of uncertain tax positions representing agreed adjustments resulting from the 2007-2009 IRS examination were reclassified to income taxes payable.

[3] On November 3, 2011, Grace received notice from the Canadian Revenue Agency that they had completed a review of Grace's Canadian transfer pricing for the years 2002, 2003, and 2004. As a result, Grace reversed $10.6 million of uncertain tax positions because they were effectively settled pursuant to ASC 740-10-25. A tax matter is effectively settled through examination when the taxing authority has completed an examination; the entity does not intend to appeal or litigate any aspect of a particular tax position for the completed examination; and based on a tax authority's widely understood policy, the entity considers it remote that the taxing authority would subsequently examine or reexamine any of the positions once the examination process is completed.

[4] In 2011, $6.7 million of uncertain tax positions representing pre-petition federal and state settlements were reclassified to income taxes payable.