Earnings Per Share

12 Months Ended

Dec. 31, 2013

Earnings Per Share [Abstract]

Earnings Per Share

7. Earnings Per Share

Basic earnings per share (“EPS”) is computed by dividing net income attributable to Amkor common shareholders 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. Unvested share-based compensation awards that contain nonforfeitable rights to dividends or dividend equivalents are considered participating securities and are included in the computation of EPS pursuant to the two-class method. We grant restricted shares which entitle recipients to voting and nonforfeitable dividend rights from the date of grant. As a result, we have applied the two-class method to determine EPS.

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 Year Ended December 31,
	2013			2012			2011
	(In thousands, except per share data)
Net income attributable to Amkor	$	109,296		$	41,818		$	91,808
Income allocated to participating securities	(681		)	(212		)	(332		)
Net income available to Amkor common stockholders	108,615			41,606			91,476
Adjustment for dilutive securities on net income:
Net income reallocated to participating securities	93			212			332
Interest on 6.0% convertible notes due 2014, net of tax	9,440			16,103			16,103
Net income attributable to Amkor — diluted	$	118,148		$	57,921		$	107,911
Weighted average shares outstanding — basic	187,032			160,105			190,829
Effect of dilutive securities:
Stock options and restricted share awards	21			241			199
6.0% convertible notes due 2014	48,277			82,658			82,658
Weighted average shares outstanding — diluted	235,330			243,004			273,686
Net income attributable to Amkor per common share:
Basic	$	0.58		$	0.26		$	0.48
Diluted	0.50			0.24			0.39

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 Year Ended December 31,
	2013	2012	2011
	(In thousands)
Stock options and restricted share awards	4,890	4,416	5,070
2.5% convertible notes due 2011	—	—	1,094
6.25% convertible notes due 2013	—	—	695
Total potentially dilutive shares	4,890	4,416	6,859