Reconciliation of Basic and Diluted Shares (Tables)

3 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Reconciliation of basic and diluted shares

	Three Months Ended
	March 31
(In thousands, except per share amounts)	2018		2017
Income from continuing operations attributable to Harsco Corporation common stockholders	$	18,260	$	9,267
Weighted-average shares outstanding - basic	80,650		80,385
Dilutive effect of stock-based compensation	2,894		1,878
Weighted-average shares outstanding - diluted	83,544		82,263
Earnings from continuing operations per common share, attributable to Harsco Corporation common stockholders:
Basic	$	0.23	$	0.12
Diluted	$	0.22	$	0.11

Schedule of antidilutive securities excluded from computation of earnings per share

The following average outstanding stock-based compensation units were not included in the computation of diluted earnings per share because the effect was antidilutive:

	Three Months Ended
	March 31
(In thousands)	2018	2017
Restricted stock units	—	—
Stock options	—	55
Stock appreciation rights	696	1,263
Performance share units	—	467