Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Net sales	$ 1,406,535	$ 1,172,909	$ 2,732,685	$ 2,325,525
Cost of sales	1,133,715	980,589	2,194,331	1,944,297
Gross profit	272,820	192,320	538,354	381,228
Selling, general and administrative	74,189	74,260	150,957	146,842
Research and development	43,516	31,536	87,834	63,789
Total operating expenses	117,705	105,796	238,791	210,631
Operating income	155,115	86,524	299,563	170,597
Interest expense	12,764	16,012	25,437	33,057
Other (income) expense, net	(96)	1,467	(7)	(848)
Total other expense, net	12,668	17,479	25,430	32,209
Income before taxes	142,447	69,045	274,133	138,388
Income tax expense	15,989	12,905	27,656	17,751
Net income	126,458	56,140	246,477	120,637
Net income attributable to non-controlling interests	(652)	(716)	(862)	(1,324)
Net income attributable to Amkor	$ 125,806	$ 55,424	$ 245,615	$ 119,313
Net income attributable to Amkor per common share:
Basic (in dollars per share)	$ 0.52	$ 0.23	$ 1.01	$ 0.50
Diluted (in dollars per share)	$ 0.51	$ 0.23	$ 1.00	$ 0.49
Shares used in computing per common share amounts:
Basic (in shares)	243,863	241,098	243,566	241,009
Diluted (in shares)	245,551	241,410	245,372	241,345