Segment Reporting and Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015 item segment	Mar. 31, 2014
Segment Reporting and Geographic Information
Number of operating segments	1
Number of reportable segments	1
Number of primary sales markets	4
Revenue reporting by market and geographic location
Total Sales	$ 98,341	$ 90,841
United States
Revenue reporting by market and geographic location
Total Sales	27,969	7,477
China
Revenue reporting by market and geographic location
Total Sales	44,282	32,838
EMEA
Revenue reporting by market and geographic location
Total Sales	8,325	10,346
Rest of World
Revenue reporting by market and geographic location
Total Sales	17,765	40,180
Lighting, Display and Power Electronics
Revenue reporting by market and geographic location
Total Sales	64,327	63,891
Advanced Packaging, MEMS and RF
Revenue reporting by market and geographic location
Total Sales	13,165	798
Scientific and Industrial
Revenue reporting by market and geographic location
Total Sales	13,635	8,486
Data Storage
Revenue reporting by market and geographic location
Total Sales	$ 7,214	$ 17,666