Related Party Transactions - Schedule of Account Receivable and Payable of Related Party Transactions (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Lite On Semiconductor
Related Party Transaction [Line Items]
Accounts receivable	$ 342	$ 301
Accounts payable	3,308	4,333
Keylink
Related Party Transaction [Line Items]
Accounts receivable	4,089	5,394
Accounts payable	5,016	4,295
Nuvoton
Related Party Transaction [Line Items]
Accounts payable	1,121	950
JCP
Related Party Transaction [Line Items]
Accounts payable	$ 317	$ 263