Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Net sales	$ 1,025,319	$ 899,284
Cost of sales	867,548	763,050
Gross profit	157,771	136,234
Selling, general and administrative	80,723	76,282
Research and development	40,929	41,568
Total operating expenses	121,652	117,850
Operating income	36,119	18,384
Interest expense	20,011	21,254
Interest expense, related party	0	1,242
Other (income) expense, net	3,432	11,181
Total other expense, net	23,443	33,677
Income (loss) before taxes	12,676	(15,293)
Income tax expense (benefit)	2,481	(1,325)
Net income (loss)	10,195	(13,968)
Net income attributable to non-controlling interests	(651)	(818)
Net income (loss) attributable to Amkor	$ 9,544	$ (14,786)
Net income (loss) attributable to Amkor per common share:
Basic (in dollars per share)	$ 0.04	$ (0.06)
Diluted (in dollars per share)	$ 0.04	$ (0.06)
Shares used in computing per common share amounts:
Basic (in shares)	239,214	238,685
Diluted (in shares)	239,816	238,685