Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues	$ 1,958.1	$ 1,932.1	$ 1,716.5
Cost of goods sold	1,164.4	1,165.4	1,040.4
Gross profit	793.7	766.7	676.1
Selling, general and administrative expenses	299.0	300.4	268.4
Research and development expenses	64.5	62.7	56.3
Costs related to legacy matters	103.5	82.3	33.1
Restructuring and repositioning expenses	13.7	46.4	26.7
Equity in earnings of unconsolidated affiliate	(27.8)	(31.8)	(25.9)
Interest expense and related financing costs	76.7	80.2	79.5
Nonoperating Income (Expense)	80.6	(18.4)	27.1
Total costs and expenses	610.2	521.8	465.2
Income (loss) before income taxes	183.5	244.9	210.9
(Provision for) benefit from income taxes	(56.8)	(78.1)	(200.5)
Net income (loss)	126.7	166.8	10.4
Less: Net (income) loss attributable to noncontrolling interests	(0.4)	0.8	0.8
Net income (loss) attributable to W. R. Grace & Co. shareholders	$ 126.3	$ 167.6	$ 11.2
Basic earnings per share attributable to W. R. Grace & Co. shareholders
Net income (loss)	$ 1.89	$ 2.49	$ 0.16
Weighted average number of basic shares	66.8	67.2	68.1
Diluted earnings per share attributable to W. R. Grace & Co. shareholders
Net income (loss)	$ 1.89	$ 2.49	$ 0.16
Weighted average number of diluted shares	66.9	67.3	68.2
Dividends per common share	$ 1.08	$ 0.96	$ 0.84