Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2020

Earnings Per Share [Abstract]

Schedule of reconciliation of the numerators and denominators used in calculating basic and diluted earnings per share

The following table shows a reconciliation of the numerators and denominators used in calculating basic and diluted earnings per share.

	Three Months Ended March 31,
(In millions, except per share amounts)	2020		2019
Numerators
Net income (loss) attributable to W. R. Grace & Co. shareholders	$	42.0	$	24.7
Denominators
Weighted average common shares—basic calculation	66.5		66.8
Dilutive effect of employee stock options	—		0.1
Weighted average common shares—diluted calculation	66.5		66.9
Basic earnings per share	$	0.63	$	0.37
Diluted earnings per share	$	0.63	$	0.37