Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
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 (in shares)	10,000us-gaap_PreferredStockSharesAuthorized	10,000us-gaap_PreferredStockSharesAuthorized
Preferred stock designated Series A, shares issued (in shares)	0us-gaap_PreferredStockSharesIssued	0us-gaap_PreferredStockSharesIssued
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	500,000us-gaap_CommonStockSharesAuthorized	500,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued (in shares)	282,231us-gaap_CommonStockSharesIssued	262,109us-gaap_CommonStockSharesIssued
Common stock, shares outstanding (in shares)	236,627us-gaap_CommonStockSharesOutstanding	216,702us-gaap_CommonStockSharesOutstanding
Treasury stock, shares	45,604us-gaap_TreasuryStockShares	45,407us-gaap_TreasuryStockShares

Face amount or stated value per share of common stock.

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