Business Segment and Foreign Operations - Long-lived Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Long-lived Assets from External Customers and Long-Lived Assets [Line Items]
Total long-lived tangible assets	$ 111,610	$ 110,247
United States
Long-lived Assets from External Customers and Long-Lived Assets [Line Items]
Total long-lived tangible assets	12,584	11,948
People's Republic of China (PRC)
Long-lived Assets from External Customers and Long-Lived Assets [Line Items]
Total long-lived tangible assets	94,753	94,113
All other countries
Long-lived Assets from External Customers and Long-Lived Assets [Line Items]
Total long-lived tangible assets	$ 4,273	$ 4,186