Revision of Previously Reported Financial Information Statement of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Foreign currency translation adjustment	$ 19,323	$ 5,783	$ (146)	$ (11,964)
Net income		167,304	53,893	133,240
Equity interest in J-Devices' other comprehensive income (loss), net of tax		0	29,433	(18,844)
Total other comprehensive income (loss)	19,347	8,346	30,387	(32,320)
Comprehensive income	18,942	175,650	84,280	100,920
Comprehensive income attributable to Amkor	18,472	$ 172,536	81,485	97,419
Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Foreign currency translation adjustment	19,864
Net income			59,607	133,887
Equity interest in J-Devices' other comprehensive income (loss), net of tax			29,829	(19,136)
Total other comprehensive income (loss)	19,888		30,783	(32,612)
Comprehensive income	19,483		90,390	101,275
Comprehensive income attributable to Amkor	19,013		87,595	97,774
Scenario, Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Foreign currency translation adjustment	(541)
Net income			(5,714)	(647)
Equity interest in J-Devices' other comprehensive income (loss), net of tax			(396)	292
Total other comprehensive income (loss)	(541)		(396)	292
Comprehensive income	(541)		(6,110)	(355)
Comprehensive income attributable to Amkor	$ (541)		$ (6,110)	$ (355)