Earnings Per Share

6 Months Ended

Jun. 30, 2014

Earnings Per Share [Abstract]

Earnings Per Share

8.    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. We grant restricted shares which entitle recipients to voting and nonforfeitable dividend rights from the date of grant therefore our unvested share-based compensation awards are considered participating securities and are included in the computation of EPS pursuant to the two-class method.

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, unvested restricted shares and convertible debt. The following table summarizes the computation of basic and diluted EPS:

	For the Three Months Ended June 30,						For the Six Months Ended June 30,
	2014			2013			2014			2013
	(In thousands, except per share data)
Net income attributable to Amkor	$	49,521		$	29,727		$	70,154		$	43,109
Income allocated to participating securities	(184		)	(251		)	(269		)	(374		)
Net income available to Amkor common stockholders — basic	49,337			29,476			69,885			42,735
Adjustment for dilutive securities on net income:
Net income reallocated to participating securities	3			58			9			80
Interest on 6.0% convertible notes due 2014, net of tax	132			3,609			1,039			7,626
Net income attributable to Amkor — diluted	$	49,472		$	33,143		$	70,933		$	50,441
Weighted average shares outstanding — basic	232,891			160,886			224,868			156,672
Effect of dilutive securities:
Stock options	1,115			10			609			14
6.0% convertible notes due 2014	2,866			74,215			10,705			78,413
Weighted average shares outstanding — diluted	236,872			235,111			236,182			235,099
Net income attributable to Amkor per common share:
Basic	$	0.21		$	0.18		$	0.31		$	0.27
Diluted	0.21			0.14			0.30			0.21

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 antidilutive:

	For the Three Months Ended June 30,		For the Six Months Ended June 30,
	2014	2013	2014	2013
	(In thousands)
Stock options and restricted share awards	1,114	4,092	1,563	4,165