Segment Reporting and Geographic Information Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Revenues	$ 52,570	$ 41,649
UNITED STATES
Segment Reporting Information [Line Items]
Revenues	17,648	9,934
TAIWAN, PROVINCE OF CHINA
Segment Reporting Information [Line Items]
Revenues	13,329	7,930
JAPAN
Segment Reporting Information [Line Items]
Revenues	1,314	1,284
CHINA
Segment Reporting Information [Line Items]
Revenues	6,088	4,830
South Korea [Domain]
Segment Reporting Information [Line Items]
Revenues	3,531	7,552
Asia [Member]
Segment Reporting Information [Line Items]
Revenues	1,777	6,591
GERMANY
Segment Reporting Information [Line Items]
Revenues	7,055	1,344
Other Europe [Domain]
Segment Reporting Information [Line Items]
Revenues	1,828	2,184
Sales [Member]
Segment Reporting Information [Line Items]
Revenues	$ 52,570	$ 41,649