Earnings Per Share

12 Months Ended

Dec. 31, 2019

Earnings Per Share [Abstract]

Earnings Per Share

Earnings Per Share

Basic earnings per share (“EPS”) is computed by dividing net income attributable to Amkor common stockholders by the weighted-average number of common shares outstanding during the period. The weighted-average number of common shares outstanding includes restricted shares held by retirement eligible recipients and is reduced for treasury stock.

Diluted EPS is computed on the basis of the weighted-average number of shares of common stock plus the effect of dilutive potential common shares outstanding during the period. Dilutive potential common shares include outstanding stock options and unvested restricted shares.

The following table summarizes the computations of basic and diluted EPS:

	For the Year Ended December 31,
	2019		2018		2017
	(In thousands, except per share data)
Net income available to Amkor common stockholders	$	120,888	$	127,092	$	263,550
Weighted-average shares outstanding — basic	239,725		239,329		238,937
Effect of dilutive securities:
Stock options and restricted share awards	397		412		714
Weighted-average shares outstanding — diluted	240,122		239,741		239,651
Net income attributable to Amkor per common share:
Basic	$	0.50	$	0.53	$	1.10
Diluted	0.50		0.53		1.10

The following table summarizes the potential shares of common stock that were excluded from diluted EPS, because the effect of including these potential shares was anti-dilutive:

	For the Year Ended December 31,
	2019	2018	2017
	(In thousands)
Stock options and restricted share awards	5,379	3,662	3,445