Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (9,006)	$ 33,184	$ (31,674)	$ 43,379
Other comprehensive income (loss), net of tax:
Adjustments to unrealized components of defined benefit pension plans	(57)	(42)	(189)	(81)
Foreign currency translation	5,918	(11,144)	3,694	3,947
Total other comprehensive income (loss)	5,861	(11,186)	3,505	3,866
Comprehensive income (loss)	(3,145)	21,998	(28,169)	47,245
Comprehensive income attributable to non-controlling interests	(444)	(593)	(655)	(1,244)
Comprehensive income (loss) attributable to Amkor	$ (3,589)	$ 21,405	$ (28,824)	$ 46,001