Debt (Details) (USD $)	1 Months Ended							3 Months Ended				3 Months Ended					3 Months Ended				3 Months Ended
	Apr. 30, 2013 Korea Subsidiaries [Member] Subsequent Event [Member]	Mar. 31, 2013 Senior Notes Due May 2018 [Member]	Mar. 31, 2013 Senior Notes Due 2021 [Member]	Mar. 31, 2013 Senior Notes Due 2021 [Member] Related Party [Member]	Mar. 31, 2013 Senior Notes Due October 2022 [Member]	Mar. 31, 2013 Convertible Senior Subordinated Notes Due April 2014 [Member]	Mar. 31, 2013 Convertible Senior Subordinated Notes Due April 2014 [Member] Related Party [Member]	Mar. 31, 2013 Term Loan Due March 2015 [Member] Korea Subsidiaries [Member]	Mar. 31, 2013 Term Loan Due July 2017 [Member] Korea Subsidiaries [Member]	Mar. 31, 2013 Term Loan Due July 2017 [Member] Korea Subsidiaries [Member] Minimum [Member]	Mar. 31, 2013 Term Loan Due July 2017 [Member] Korea Subsidiaries [Member] Maximum [Member]	Mar. 31, 2013 Term Loan Due April 2015 [Member] Taiwan Subsidiaries [Member]	Mar. 31, 2013 Term Loan Due September 2017 [Member] Korea Subsidiaries [Member]	Mar. 31, 2013 Term Loan Due December 2019 [Member] Korea Subsidiaries [Member]	Mar. 31, 2013 Revolving Credit Facility Due April 2015 [Member] Taiwan Subsidiaries [Member]	Dec. 31, 2012 Revolving Credit Facility Due April 2015 [Member] Taiwan Subsidiaries [Member]	Mar. 31, 2013 $150 million revolving credit facility, LIBOR plus 1.5%-2.25%, due June 2017 [Member]	Dec. 31, 2012 $150 million revolving credit facility, LIBOR plus 1.5%-2.25%, due June 2017 [Member]	Mar. 31, 2013 $150 million revolving credit facility, LIBOR plus 1.5%-2.25%, due June 2017 [Member] Minimum [Member]	Mar. 31, 2013 $150 million revolving credit facility, LIBOR plus 1.5%-2.25%, due June 2017 [Member] Maximum [Member]	Mar. 31, 2013 Revolving Credit Facility 2.33% due June 2013 [Member] Korea Subsidiaries [Member]	Dec. 31, 2012 Revolving Credit Facility 2.33% due June 2013 [Member] Korea Subsidiaries [Member]
Debt Instruments [Abstract]
Credit facility, borrowing capacity	$ 150,000,000.0												$ 150,000,000.0	$ 100,000,000.0	$ 44,000,000.0		$ 150,000,000				$ 41,000,000
Debt Instrument, Periodic Payment, Principal													5,000,000
Basis spread on variable rate (percentage)	3.80%							2.30%		3.90%	3.94%		1.75%	3.70%					1.50%	2.25%	2.33%
Debt, interest rate terms								foreign currency funding-linked rate plus 2.30%	LIBOR plus 3.90% or 3.94%			TAIFX plus a bank-determined spread	foreign currency funding-linked base rate plus 1.75%	LIBOR plus 3.70%			LIBOR plus 1.5%-2.25%				foreign currency funding-linked base rate plus 2.33%
Interest rate on convertible notes due (percentage)		7.375%	6.625%		6.375%	6.00%
Face amount for related party				75,000,000			150,000,000
Debt Instrument Term	3 years												4 years 6 months	7 years
Interest rate for debt (percentage)													3.58%	4.00%
Borrowings outstanding															0	0	0	0			0	0
Current borrowing capacity													140,000,000	77,000,000	39,000,000
Line of Credit Facility, Step Down Provision															$ 5,000,000