Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Net sales	$ 1,172,909	$ 895,305	$ 2,325,525	$ 1,790,269
Cost of sales	980,589	771,851	1,944,297	1,546,054
Gross profit	192,320	123,454	381,228	244,215
Selling, general and administrative	74,260	64,758	146,842	136,345
Research and development	31,536	36,186	63,789	71,940
Total operating expenses	105,796	100,944	210,631	208,285
Operating income	86,524	22,510	170,597	35,930
Interest expense	16,012	18,653	33,057	37,926
Other (income) expense, net	1,467	6,966	(848)	2,401
Total other expense, net	17,479	25,619	32,209	40,327
Income (loss) before taxes	69,045	(3,109)	138,388	(4,397)
Income tax expense	12,905	5,897	17,751	27,277
Net income (loss)	56,140	(9,006)	120,637	(31,674)
Net income attributable to non-controlling interests	(716)	(444)	(1,324)	(655)
Net income (loss) attributable to Amkor	$ 55,424	$ (9,450)	$ 119,313	$ (32,329)
Net income (loss) attributable to Amkor per common share:
Basic (in dollars per share)	$ 0.23	$ (0.04)	$ 0.50	$ (0.14)
Diluted (in dollars per share)	$ 0.23	$ (0.04)	$ 0.49	$ (0.14)
Shares used in computing per common share amounts:
Basic (in shares)	241,098	239,508	241,009	239,461
Diluted (in shares)	241,410	239,508	241,345	239,461