Equity and Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Schedule of Stockholders Equity and Comprehensive Income [Line Items]
Equity, Beginning balance			$ 666,794	$ 701,221
Net income	26,004	22,576	70,099	35,030
Other comprehensive (loss) income	2,533	1,433	(4,401)	1,706
Issuance of stock through employee share-based compensation plans				181
Treasury stock acquired through surrender of shares for tax withholding			(234)	(546)
Share-based compensation expense			2,065	2,048
Repurchase of common stock				(79,814)
Exchange of debt for common stock			195,034
Equity, Ending balance	929,357	659,826	929,357	659,826
Amkor [Member]
Schedule of Stockholders Equity and Comprehensive Income [Line Items]
Equity, Beginning balance			657,955	693,266
Net income			68,458	34,672
Other comprehensive (loss) income			(4,401)	1,706
Issuance of stock through employee share-based compensation plans				181
Treasury stock acquired through surrender of shares for tax withholding			(234)	(546)
Share-based compensation expense			2,065	2,048
Repurchase of common stock				(79,814)
Exchange of debt for common stock			195,034
Equity, Ending balance	918,877	651,513	918,877	651,513
Noncontrolling Interest [Member]
Schedule of Stockholders Equity and Comprehensive Income [Line Items]
Equity, Beginning balance			8,839	7,955
Net income			1,641	358
Other comprehensive (loss) income			0	0
Issuance of stock through employee share-based compensation plans				0
Treasury stock acquired through surrender of shares for tax withholding			0	0
Share-based compensation expense			0	0
Repurchase of common stock				0
Exchange of debt for common stock			0
Equity, Ending balance	$ 10,480	$ 8,313	$ 10,480	$ 8,313