Pension and Severance Plans Textuals (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Non-current (Pension and severance obligations)	$ 135,578,000		$ 139,379,000
Korean Severance Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued severance plan, minimum service period	1 year
Provision for severance benefit	5,500,000	400,000
Current (Accrued expenses)	10,078,000		9,516,000
Non-current (Pension and severance obligations)	113,936,000		116,997,000
Pension and Other Postretirement and Postemployment Benefit Plans, Liabilities	124,014,000		126,513,000
Foreign Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions to pension plans	100,000
Expected employer contribution during remaining part of Year	2,300,000
Japan Subsidiaries [Member]
Defined Benefit Plan Disclosure [Line Items]
Curtailment and settlement losses		$ 1,000,000