Operating Segment Information - Reportable Segment Data (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) segment	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment			3
Net Sales
Net sales	$ 390.5	$ 407.2	$ 753.3	$ 804.2
Adjusted EBIT
Total	96.1	82.4	178.7	153.9
Total Assets
Assets	2,981.6		2,981.6		$ 3,645.7
Assets of discontinued operations	0.0		0.0		867.3
Reconciliation of operating segment data to financial statements
Grace Adjusted EBIT	96.1	82.4	178.7	153.9
Restructuring and repositioning expenses	(9.4)	(4.2)	(23.0)	(9.7)
(Costs) benefit related to Chapter 11, and legacy product and environmental, net	6.7	2.8	11.1	(6.8)
Third-party acquisition-related costs	(2.5)	0.0	(2.5)	0.0
Pension MTM adjustment and other related costs, net	0.7	0.0	0.9	(4.2)
Gain on sale of product line	0.7	0.0	0.7	0.0
Income and expense items related to divested businesses	0.1	(0.3)	(0.2)	0.5
Loss on early extinguishment of debt	0.0	0.0	(11.1)	0.0
Interest expense, net	(19.4)	(24.6)	(41.2)	(49.1)
Net loss attributable to noncontrolling interests	(0.2)	0.0	(0.4)	0.0
Income from continuing operations before income taxes	59.4	50.5	90.8	98.2
Grace Catalysts Technologies
Adjusted EBIT
Operating income	87.5	86.6	165.8	160.3
Grace Materials Technologies
Adjusted EBIT
Operating income	28.0	23.8	48.6	47.7
Corporate, Non-Segment [Member]
Adjusted EBIT
Operating income			(29.5)	(43.8)
Certain pension costs	(3.1)	(5.0)	(6.2)	(10.3)
Operating Segments | Grace Catalysts Technologies
Net Sales
Net sales	278.4	289.3	539.0	570.3
Total Assets
Assets	1,618.7		1,618.7		1,390.8
Operating Segments | Grace Materials Technologies
Net Sales
Net sales	112.1	117.9	214.3	$ 233.9
Total Assets
Assets	306.8		306.8		333.4
Corporate, Non-Segment [Member]
Adjusted EBIT
Operating income	(16.3)	$ (23.0)
Total Assets
Assets	$ 1,056.1		$ 1,056.1		$ 1,054.2