Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Amkor stockholders’ equity:
Allowance	$ 9,902	$ 3,158
Preferred stock designated Series A, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock designated Series A, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock designated Series A, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	284,479,000	282,724,000
Common stock, shares outstanding (in shares)	238,665,000	237,005,000
Treasury stock, shares	45,814,000	45,719,000