Revision of Previously Reported Financial Information Statement of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income	$ 61,141		$ 28,582	$ 66,102	$ 64,046
Equity interest in J-Devices' other comprehensive income, net of tax	0		4,394	0	509
Foreign currency translation	5,883	$ 19,323	10	52,161	(102)
Total other comprehensive loss	5,907	19,347	4,426	52,232	473
Comprehensive income	67,048	18,942	33,008	118,334	64,519
Comprehensive income attributable to Amkor	$ 65,996	18,472	32,161	$ 116,159	62,133
Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income			29,021		68,919
Equity interest in J-Devices' other comprehensive income, net of tax			4,587		537
Foreign currency translation		19,864
Total other comprehensive loss		19,888	4,619		501
Comprehensive income		19,483	33,640		69,420
Comprehensive income attributable to Amkor		19,013	32,793		67,034
Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income			(439)		(4,873)
Equity interest in J-Devices' other comprehensive income, net of tax			(193)		(28)
Foreign currency translation		(541)
Total other comprehensive loss		(541)	(193)		(28)
Comprehensive income		(541)	(632)		(4,901)
Comprehensive income attributable to Amkor		$ (541)	$ (632)		$ (4,901)