Segment Reporting and Geographic Information - (Tables)

6 Months Ended

Jun. 30, 2015

Segment Reporting and Geographic Information [Abstract]

Schedule of revenue from external customers by Products and Services [Table Text Block]

The following table lists the different sources of revenue:

	Three Months Ended								Six Months Ended
	June 30,								June 30,
	2015				2014				2015				2014
Systems and Software:
Inspection	$	32,225	54	%	$	22,852	53	%	$	60,686	54	%	$	40,853	48	%
Metrology	9,645		16	%	4,652		11	%	17,245		16	%	10,401		12	%
Data Analysis and Review	5,142		9	%	6,956		16	%	12,936		12	%	12,930		15	%
Lithography	3,826		6	%	—		—	%	3,847		3	%	3,657		5	%
Parts	5,796		10	%	5,072		12	%	11,451		10	%	10,112		12	%
Services	2,832		5	%	3,486		8	%	5,871		5	%	6,714		8	%
Total revenue	$	59,466	100	%	$	43,018	100	%	$	112,036	100	%	$	84,667	100	%

Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block]

For geographical revenue reporting, revenues are attributed to the geographic location in which the product is shipped.  Revenue by geographic region is as follows:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2015		2014		2015		2014
United States	$	11,773	$	9,704	$	29,420	$	19,638
Taiwan	16,259		12,252		29,588		20,182
Japan	3,918		5,068		5,232		6,353
China	858		2,295		6,945		7,125
South Korea	6,709		887		10,240		8,439
Other Asia	9,359		5,995		11,137		12,586
Germany	8,970		3,908		16,025		5,251
Other Europe	1,620		2,909		3,449		5,093
Total revenue	$	59,466	$	43,018	$	112,036	$	84,667

Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]

The following customer accounted for more than 10% of total revenues for the indicated periods.

	Six Months Ended
	June 30,
	2015		2014
Customer A	6.4	%	11.1	%