Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 171,228	$ 120,019
Other comprehensive income (loss), net of tax:
Adjustments to net unrealized gains (losses) on available-for-sale debt investments	(1,077)	(32)
Adjustments to unrealized components of defined benefit pension plans	4	25
Foreign currency translation	(8,409)	(11,440)
Total other comprehensive income (loss)	(9,482)	(11,447)
Comprehensive income	161,746	108,572
Comprehensive income attributable to non-controlling interests	(565)	(210)
Comprehensive income attributable to Amkor	$ 161,181	$ 108,362