Geographic Data - Schedule of Revenue by Geographic Areas (Details 2) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, Plant and Equipment, Net	$ 99,401	$ 88,247
United States | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, Plant and Equipment, Net	53,950	44,010
China | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, Plant and Equipment, Net	32,973	32,464
Taiwan | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, Plant and Equipment, Net	3,752	3,540
Czech Republic | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, Plant and Equipment, Net	5,976	5,518
Other non-U.S | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, Plant and Equipment, Net	$ 2,750	$ 2,715