Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares shares in Thousands	Jun. 30, 2015	Dec. 31, 2014
Amkor stockholders’ equity:
Preferred stock designated Series A, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock designated Series A, shares authorized	10,000	10,000
Preferred stock designated Series A, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	500,000	500,000
Common stock, shares issued	282,532	282,231
Common stock, shares outstanding	236,869	236,627
Treasury stock, shares	45,663	45,604