Earnings Per Share

6 Months Ended

Jun. 30, 2011

Earnings Per Share [Abstract]

Earnings Per Share

5.   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 excludes 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 earnings per share pursuant to the two-class method. As discussed in Note 3, 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 earnings per share.

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						For the Six Months
	Ended June 30,						Ended June 30,
	2011			2010			2011			2010
	(In thousands, except per share data)
Net income attributable to Amkor	$	14,488		$	59,050		$	39,591		$	103,347
Income allocated to participating securities		(58	)		(123	)		(161	)		(215	)
Net income available to Amkor common stockholders		14,430			58,927			39,430			103,132
Adjustment for dilutive securities on net income:
Net income allocated to participating securities in basic calculation		58						161
Interest on 2.5% convertible notes due 2011, net of tax		—			329			—			659
Interest on 6.25% convertible notes due 2013, net of tax		—			1,592			—			3,185
Interest on 6.0% convertible notes due 2014, net of tax		4,026			4,026			8,052			8,052
Net income attributable to Amkor — diluted	$	18,514		$	64,874		$	47,643		$	115,028
Weighted average shares outstanding — basic		197,084			183,274			195,584			183,250
Effect of dilutive securities:
Stock options		232			364			313			333
Unvested restricted shares		35			79			255			41
2.5% convertible notes due 2011		—			2,918			—			2,918
6.25% convertible notes due 2013		—			13,351			—			13,351
6.0% convertible notes due 2014		82,658			82,658			82,658			82,658
Weighted average shares outstanding — diluted		280,009			282,644			278,810			282,551
Net income attributable to Amkor per common share:
Basic	$	0.07		$	0.32		$	0.20		$	0.56
Diluted		0.07			0.23			0.17			0.41

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				For the Six
	Months Ended				Months Ended
	June 30,				June 30,
	2011		2010		2011		2010
	(In thousands, except per share data)
Stock options		5,325		6,828		5,324		6,828
2.5% convertible notes due 2011		1,459		—		2,189		—
6.25% convertible notes due 2013		—		—		1,402		—
Total potentially dilutive shares		6,784		6,828		8,915		6,828