Bank Credit Agreements and Other Short-Term and Long-Term Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total long-term debt	$ 98,641	$ 215,191
Current portion of long-term debt	(33,105)	(27,613)
Less: Unamortized debt issuance costs	(1,135)	(1,435)
Long-term debt, net of current portion	64,401	186,143
Notes Payable to Bank | Bank of Taiwan
Debt Instrument [Line Items]
Total long-term debt	4,242	4,442
Notes Payable to Bank | Yuan Ta Bank
Debt Instrument [Line Items]
Total long-term debt		749
Notes Payable to Bank | China Trust Bank
Debt Instrument [Line Items]
Total long-term debt	19,212
Term Loan and Revolver
Debt Instrument [Line Items]
Total long-term debt	$ 75,187	$ 210,000