Segment Reporting and Geographic Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) item segment	Mar. 31, 2018 USD ($)
Revenue reporting by end-market and geographic region
Number of operating segments | segment	1
Number of reportable segments | segment	1
Number of key markets | item	4
Sale by end-market	$ 99,371	$ 158,574
United States
Revenue reporting by end-market and geographic region
Sale by end-market	32,315	23,754
China
Revenue reporting by end-market and geographic region
Sale by end-market	10,159	75,395
EMEA
Revenue reporting by end-market and geographic region
Sale by end-market	17,827	15,745
Rest Of World
Revenue reporting by end-market and geographic region
Sale by end-market	39,070	43,680
Advanced Packaging, MEMS & RF Filters
Revenue reporting by end-market and geographic region
Sale by end-market	23,127	27,153
LED Lighting, Display & Compound Semiconductor
Revenue reporting by end-market and geographic region
Sale by end-market	13,550	89,916
Front-End Semiconductor
Revenue reporting by end-market and geographic region
Sale by end-market	22,617	9,457
Scientific & Industrial
Revenue reporting by end-market and geographic region
Sale by end-market	$ 40,077	$ 32,048