Consolidated Statements of Operations (unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net sales	$ 802.8	$ 826.7	$ 1,512.7	$ 1,581.1
Cost of goods sold	499.5	522.6	945.6	999.9
Gross profit	303.3	304.1	567.1	581.2
Selling, general and administrative expenses	137.6	133.8	266.5	270.4
Restructuring expenses and related asset impairments	4.3	2.3	5.1	5.3
Research and development expenses	16.6	16.0	33.5	32.5
Defined benefit pension expense	18.1	16.8	36.7	35.6
Interest expense and related financing costs	10.9	11.3	21.4	22.6
Provision for environmental remediation	1.3	0.6	2.3	1.2
Chapter 11 expenses, net of interest income	3.3	3.7	8.1	8.2
Libby medical program settlement	0	19.5	0	19.5
Equity in earnings of unconsolidated affiliate	(9.2)	(3.2)	(14.3)	(8.9)
Other (income) expense, net	(1.7)	(2.2)	4.4	(2.8)
Total costs and expenses	181.2	198.6	363.7	383.6
Income before income taxes	122.1	105.5	203.4	197.6
Provision for income taxes	(38.8)	(35.8)	(66.9)	(66.6)
Net income	83.3	69.7	136.5	131.0
Less: Net income attributable to noncontrolling interests	(0.5)	(0.4)	(0.8)	(0.8)
Net income attributable to W. R. Grace & Co. shareholders	$ 82.8	$ 69.3	$ 135.7	$ 130.2
Basic earnings per share:
Net income attributable to W. R. Grace & Co. shareholders (in dollars per share)	$ 1.09	$ 0.93	$ 1.79	$ 1.75
Weighted average number of basic shares	76.3	74.7	76.0	74.5
Diluted earnings per share:
Net income attributable to W. R. Grace & Co. shareholders (in dollars per share)	$ 1.07	$ 0.90	$ 1.75	$ 1.70
Weighted average number of diluted shares	77.6	76.6	77.4	76.5