Revision of Previously Reported Financial Information Income Statement (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other (income) expense, net	$ (5,854)	$ 10,551	$ (24,543)
Equity in earnings of J-Devices	0	14,016	31,007
Net income	167,304	53,893	133,240
Net income attributable to Amkor	$ 164,190	$ 51,098	$ 129,739
Basic (in dollars per share)	$ 0.69	$ 0.22	$ 0.56
Diluted (in dollars per share)	$ 0.69	$ 0.22	$ 0.55
Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other (income) expense, net		$ 10,928	$ (24,543)
Equity in earnings of J-Devices		20,107	31,654
Net income		59,607	133,887
Net income attributable to Amkor		$ 56,812	$ 130,386
Basic (in dollars per share)		$ 0.24	$ 0.56
Diluted (in dollars per share)		$ 0.24	$ 0.55
Scenario, Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other (income) expense, net		$ (377)	$ 0
Equity in earnings of J-Devices		(6,091)	(647)
Net income		(5,714)	(647)
Net income attributable to Amkor		$ (5,714)	$ (647)
Basic (in dollars per share)		$ (0.02)	$ 0.00
Diluted (in dollars per share)		$ (0.02)	$ 0.00