Segment Reporting and Geographic Information - (Tables)

3 Months Ended

Mar. 31, 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
	March 31,
	2015				2014
Systems and Software:
Inspection	$	28,462	54	%	$	18,002	43	%
Metrology	7,599		15	%	5,749		14	%
Data Analysis and Review	7,794		15	%	5,974		14	%
Lithography	21		—	%	3,657		9	%
Parts	5,655		10	%	5,040		12	%
Services	3,039		6	%	3,227		8	%
Total revenue	$	52,570	100	%	$	41,649	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
	March 31,
	2015		2014
United States	$	17,648	$	9,934
Taiwan	13,329		7,930
Japan	1,314		1,284
China	6,088		4,830
South Korea	3,531		7,552
Other Asia	1,777		6,591
Germany	7,055		1,344
Other Europe	1,828		2,184
Total revenue	$	52,570	$	41,649

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

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

	Three Months Ended
	March 31,
	2015		2014
Customer A	11.1	%	4.5	%
Customer B	10.2	%	—	%
Customer C	2.2	%	14.0	%
Customer D	0.9	%	17.0	%