Capital Stock

The authorized capital stock of the Company consists of 150,000,000 shares of common stock and 4,000,000 shares of preferred stock, both having a par value of $1.25 per share. The preferred stock is issuable in series with terms as fixed by the Board of Directors (the "Board"). No preferred stock has been issued. The following table summarizes the Company's common stock:



	Shares Issued	Treasury Shares (a)	Outstanding Shares
Outstanding, January 1, 2015	112,357,348	31,697,498	80,659,850
Shares issued for vested restricted stock units	47,954	16,807	31,147
Treasury shares purchased	—	596,632	(596,632	)
Outstanding, December 31, 2015	112,405,302	32,310,937	80,094,365
Shares issued for vested restricted stock units	94,572	13,974	80,598
Outstanding, December 31, 2016	112,499,874	32,324,911	80,174,963
Shares issued for vested restricted stock units	375,355	105,431	269,924
Stock appreciation rights exercised	12,897	3,932	8,965
Outstanding, December 31, 2017	112,888,126	32,434,274	80,453,852


(a)	The Company repurchases shares in connection with the issuance of shares under stock-based compensation programs and in accordance with Board authorized share repurchase programs.

The following is a reconciliation of the average shares of common stock used to compute basic earnings per common share to the shares used to compute diluted earnings per common share as shown on the Consolidated Statements of Operations:



(In thousands, except per share data)	2017		2016			2015
Income (loss) from continuing operations attributable to Harsco Corporation common stockholders	$	7,626	$	(86,336	)	$	7,168

Weighted-average shares outstanding—basic	80,553		80,333			80,234
Dilutive effect of stock-based compensation	2,287		—			131
Weighted-average shares outstanding—diluted	82,840		80,333			80,365
Income (loss) from continuing operations per common share, attributable to Harsco Corporation common stockholders:
Basic	$	0.09	$	(1.07	)	$	0.09

Diluted	$	0.09	$	(1.07	)	$	0.09

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



(In thousands)	2017	2016	2015
Restricted stock units	—	810	—
Stock options	52	89	98
Stock appreciation rights	811	1,458	1,142
Performance share units	201	684	278