Business Segment and Foreign Operations - Long-lived Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Long-lived Assets from External Customers and Long-Lived Assets [Line Items]
Long-lived tangible assets	$ 98,870	$ 95,380
United States [Member]
Long-lived Assets from External Customers and Long-Lived Assets [Line Items]
Long-lived tangible assets	7,524	7,015
People's Republic of China [Member]
Long-lived Assets from External Customers and Long-Lived Assets [Line Items]
Long-lived tangible assets	86,419	83,794
All Other Countries [Member]
Long-lived Assets from External Customers and Long-Lived Assets [Line Items]
Long-lived tangible assets	$ 4,927	$ 4,571