Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 181,847	$ 92,897	$ 428,324	$ 213,534
Other comprehensive income (loss), net of tax:
Adjustments to net unrealized gains (losses) on available-for-sale debt investments	(101)	(165)	(147)	193
Adjustments to unrealized components of defined benefit pension plans	26	11	77	34
Foreign currency translation	(102)	4,191	(11,264)	3,967
Total other comprehensive income (loss)	(177)	4,037	(11,334)	4,194
Comprehensive income	181,670	96,934	416,990	217,728
Comprehensive income attributable to non-controlling interests	(993)	(746)	(1,855)	(2,070)
Comprehensive income attributable to Amkor	$ 180,677	$ 96,188	$ 415,135	$ 215,658