Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2019

Earnings Per Share [Abstract]

Computation of basic and diluted earnings per share

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

	For the Three Months Ended March 31,
	2019			2018
	(In thousands, except per share data)
Net income (loss) attributable to Amkor common stockholders	$	(22,879	)	$	9,544
Weighted-average number of common shares outstanding — basic	239,414			239,214
Effect of dilutive securities:
Stock options and restricted share awards	—			602
Weighted-average number of common shares outstanding — diluted	239,414			239,816
Net income (loss) attributable to Amkor per common share:
Basic	$	(0.10	)	$	0.04
Diluted	(0.10		)	0.04

Summary of potential shares of common stock excluded from diluted earnings per share

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 Three Months Ended March 31,
	2019	2018
	(In thousands)
Stock options and restricted share awards	7,123	3,369