Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2016

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)	2016			2015
Numerators
Net income from continuing operations attributable to W. R. Grace & Co. shareholders	$	7.2		$	30.2
(Loss) income from discontinued operations	(9.9		)	22.5
Net (loss) income attributable to W. R. Grace & Co. shareholders	$	(2.7	)	$	52.7
Denominators
Weighted average common shares—basic calculation	70.6			72.8
Dilutive effect of employee stock options	—			0.7
Weighted average common shares—diluted calculation	70.6			73.5
Basic earnings per share
Net income from continuing operations attributable to W. R. Grace & Co. shareholders	$	0.10		$	0.41
(Loss) income from discontinued operations	(0.14		)	0.31
Net (loss) income attributable to W. R. Grace & Co. shareholders	$	(0.04	)	$	0.72
Diluted earnings per share
Net income from continuing operations attributable to W. R. Grace & Co. shareholders	$	0.10		$	0.41
(Loss) income from discontinued operations	(0.14		)	0.31
Net (loss) income attributable to W. R. Grace & Co. shareholders	$	(0.04	)	$	0.72