Segment Reporting and Geographic Information Geographic Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Revenues	$ 54,362	$ 52,570
UNITED STATES
Segment Reporting Information [Line Items]
Revenues	7,388	17,648
TAIWAN, PROVINCE OF CHINA
Segment Reporting Information [Line Items]
Revenues	22,035	13,329
JAPAN
Segment Reporting Information [Line Items]
Revenues	2,937	1,314
CHINA
Segment Reporting Information [Line Items]
Revenues	8,825	6,088
South Korea [Domain]
Segment Reporting Information [Line Items]
Revenues	1,623	3,531
Asia [Member]
Segment Reporting Information [Line Items]
Revenues	871	39
GERMANY
Segment Reporting Information [Line Items]
Revenues	697	7,055
Other Europe [Domain]
Segment Reporting Information [Line Items]
Revenues	2,939	1,828
Sales [Member]
Segment Reporting Information [Line Items]
Revenues	$ 54,362	$ 52,570