Description of Business and Summary of Significant Accounting Policies (Long-lived assets by geographic location) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Long-Lived Assets [Line Items]
Total	$ 28,044	$ 26,120	$ 32,436
United States
Long-Lived Assets [Line Items]
Total	14,443	19,267	22,267
China
Long-Lived Assets [Line Items]
Total	1,107	1,477	4,148
KOREA, REPUBLIC OF
Long-Lived Assets [Line Items]
Total	4,398	0	0
Switzerland
Long-Lived Assets [Line Items]
Total	$ 8,096	$ 5,376	$ 6,021