Quarterly Results (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2020

Quarterly Financial Information Disclosure [Abstract]

The following table sets forth our consolidated unaudited financial data for the last eight quarters ended December 31, 2020. We believe that we have included all adjustments, consisting only of normal recurring adjustments necessary for a fair statement of our selected quarterly data. The calculation of basic and diluted per share amounts for each quarter is based on the weighted-average shares outstanding for that period; consequently, the sum of the quarters may not necessarily be equal to the full year basic and diluted net income per share.


	For the Quarter Ended
	Dec 31, 2020 (a)		Sept 30, 2020		Jun 30, 2020		Mar 31, 2020		Dec 31, 2019 (b)		Sept 30, 2019		Jun 30, 2019 (c)		Mar 31, 2019 (d)
	(In thousands, except per share data)
Net sales	$	1,371,041	$	1,354,023	$	1,172,909	$	1,152,616	$	1,178,464	$	1,083,917	$	895,305	$	894,964

Gross profit	278,501		241,085		192,320		188,908		222,984		182,240		123,454		120,761



Operating income	159,179		127,469		86,524		84,073		118,385		78,855		22,510		13,420



Income tax expense	12,679		15,753		12,905		4,846		764		9,141		5,897		21,380
Net income (loss)	126,965		92,897		56,140		64,497		99,816		54,486		(9,006)		(22,668)

Net income (loss) attributable to Amkor	126,674		92,151		55,424		63,889		99,147		54,070		(9,450)		(22,879)
Net income (loss) attributable to Amkor per common share:
Basic	$	0.52	$	0.38	$	0.23	$	0.27	$	0.41	$	0.23	$	(0.04)	$	(0.10)
Diluted	$	0.52	$	0.38	$	0.23	$	0.26	$	0.41	$	0.23	$	(0.04)	$	(0.10)

(a)In the fourth quarter of 2020, we recorded a $20.2 million discrete tax benefit from the recognition of deferred tax assets we expect to utilize in future years.

(b)In the fourth quarter of 2019, we recorded a $3.8 million discrete income tax benefit, primarily related to changes in the valuation of certain deferred tax assets.

(c)In the second quarter of 2019, we incurred an $8.4 million charge related to the early redemption of our 2022 Notes.

(d)In the first quarter of 2019, we recorded a $14.9 million non-cash discrete income tax charge to reduce the value of certain deferred tax assets.