Income Taxes (Details 3) (USD $) In Millions, unless otherwise specified	1 Months Ended		12 Months Ended
	Feb. 28, 2014	Nov. 30, 2011	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Income Tax Disclosure [Abstract]
Amount of unrecognized tax benefits			$ 84.4	$ 88.6		$ 69.3
Amount of unrecognized tax benefits, excluding interest and penalties			80.3	83.1		62.4
Roll forward of uncertain tax positions
Additions for current year tax positions			6.3	3.4		0.6
Additions for prior year tax positions			6.4	22.0		0.5
Reductions for prior year tax positions and reclassifications		(10.6)	(9.6)	(0.8)	[1],[2]	(17.8)	[3],[4]
Settlements				(1.0)		(0.1)	[4]
Reductions for expirations of statute of limitations			(5.9)	(2.9)
Balance at the end of the period			80.3	83.1		62.4		79.2
Amount of uncertain tax position reversed		(10.6)	(9.6)	(0.8)	[1],[2]	(17.8)	[3],[4]
Material change to aggregate recorded liabilities for uncertain tax positions in the next twelve months
Change in Federal Deferred Tax Assets, Year Over Year			123.8
Amount of Uncertain Tax Position Reclassified to Income Taxes Payable						6.7
Period in Which Liability for Unrecognized Tax Benefits Could Decrease			0 years 12 months
Net Operating Losses From Emergence	670
Unrecognized tax benefits, net of indemnification			79.5	82.1
Indemnification assets that would be indemnified by a third party			0.8	1.0
Accrued interest and penalties related to uncertain tax positions			4.1	5.5		6.9
US Federal Income Tax Deduction Upon Settlement of Warrant Held by Asbestos Trusts			490
US Federal Income Tax Deduction Upon Payment of Deferred Payment Obligations			1,580
Change in Net Deferred Tax Assets, Year Over Year			98.1
Examination issues and settlements with U.S. federal, state, and foreign tax authorities
Material change to aggregate recorded liabilities for uncertain tax positions in the next twelve months
Decrease in unrecognized tax benefits during the next 12 months			$ 68

[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.