Bank Credit Agreements and Other Short-Term and Long-Term Debt - Schedule of Debt (Details) In Thousands, unless otherwise specified	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2014 Notes Payable To Bank 1 USD ($)	Dec. 31, 2014 Notes Payable To Bank 1 TWD	Dec. 31, 2013 Notes Payable To Bank 1 USD ($)	Dec. 31, 2013 Notes Payable To Bank 2 USD ($)	Dec. 31, 2014 Revolver USD ($)	Dec. 31, 2013 Revolver USD ($)
Debt Instrument [Line Items]
Long-term Debt, Gross			$ 2,074	158,000	$ 2,500	$ 2,426	$ 139,000	$ 179,000
Total long-term debt	141,074	183,926
Current portion of long-term debt	(287)	(1,127)
Long-term debt, net of current portion	$ 140,787	$ 182,799