Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net sales	$ 1,681,000	$ 1,354,023	$ 4,413,685	$ 3,679,548
Cost of sales	1,356,168	1,112,938	3,550,499	3,057,235
Gross profit	324,832	241,085	863,186	622,313
Selling, general and administrative	72,581	77,781	223,538	224,623
Research and development	40,790	35,835	128,624	99,624
Total operating expenses	113,371	113,616	352,162	324,247
Operating income	211,461	127,469	511,024	298,066
Interest expense	12,896	16,404	38,333	49,461
Other (income) expense, net	(501)	2,415	(508)	1,567
Total other expense, net	12,395	18,819	37,825	51,028
Income before taxes	199,066	108,650	473,199	247,038
Income tax expense	17,219	15,753	44,875	33,504
Net income	181,847	92,897	428,324	213,534
Net income attributable to non-controlling interests	(993)	(746)	(1,855)	(2,070)
Net income attributable to Amkor	$ 180,854	$ 92,151	$ 426,469	$ 211,464
Net income attributable to Amkor per common share:
Basic (in dollars per share)	$ 0.74	$ 0.38	$ 1.75	$ 0.88
Diluted (in dollars per share)	$ 0.74	$ 0.38	$ 1.74	$ 0.87
Shares used in computing per common share amounts:
Basic (in shares)	244,100	241,675	243,746	241,232
Diluted (in shares)	245,942	242,592	245,611	241,937