Operating Segment Information - Reportable Segment Data (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) segment	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Operating segment information
Number of Reportable Segments | segment			2
Number of operating segments | segment			2
Net Sales
Net sales	$ 429.5	$ 390.5	$ 827.5	$ 753.3
Adjusted EBIT
Total	104.0	96.1	190.8	178.7
Total Assets
Assets	2,989.9		2,989.9		$ 2,911.8
Reconciliation of operating segment data to financial statements
(Costs) benefit related to legacy product, environmental and other claims	14.9	6.7	17.0	11.1
Restructuring and repositioning expenses	5.4	9.4	7.7	23.0
Pension MTM adjustment and other related costs, net	0.0	(0.7)	1.9	(0.9)
Income and expense items related to divested businesses	0.7	(0.1)	1.0	0.2
Third-party acquisition-related costs	0.0	2.5	0.0	2.5
Gain on sale of product line	0.0	0.7	0.0	0.7
Loss on early extinguishment of debt	0.0	0.0	0.0	(11.1)
Interest expense, net	(19.5)	(19.4)	(38.8)	(41.2)
Net income (loss) attributable to noncontrolling interests	0.4	0.2	0.4	0.4
Income (loss) from continuing operations before income taxes	63.1	59.4	$ 124.0	90.8
Grace Catalysts Technologies [Member]
Operating segment information
Number of Reportable Segments | segment			1
Adjusted EBIT
Operating income	101.3	87.5	$ 182.5	165.8
Grace Materials Technologies [Member]
Adjusted EBIT
Operating income	24.2	28.0	49.0	48.6
Corporate, Non-Segment [Member]
Adjusted EBIT
Operating income			(34.4)	(29.5)
Certain pension costs	(3.2)	(3.1)	(6.3)	(6.2)
Operating Segments | Grace Catalysts Technologies [Member]
Net Sales
Net sales	320.5	278.4	614.3	539.0
Operating Segments | Grace Materials Technologies [Member]
Net Sales
Net sales	109.0	112.1	$ 213.2	$ 214.3
Corporate, Non-Segment [Member]
Adjusted EBIT
Operating income	$ (18.3)	$ (16.3)