Segment Reporting and Geographic Information (Tables)

12 Months Ended

Dec. 31, 2014

Segment Reporting and Geographic Information [Abstract]

Revenue from External Customers by Products and Services [Table Text Block]

The following table lists the different sources of revenue:

	Year Ended December 31,
	2012				2013				2014
Systems and software:
Inspection	$	128,917	59	%	$	89,089	51	%	$	87,818	49	%
Metrology	38,001		17	%	26,500		15	%	24,590		14	%
Data analysis and review	19,840		9	%	17,927		10	%	24,042		13	%
Lithography	—		—	%	8,548		5	%	11,163		6	%
Parts	20,802		10	%	21,078		12	%	20,334		11	%
Services	10,926		5	%	13,096		7	%	13,271		7	%
Total revenue	$	218,486	100	%	$	176,238	100	%	$	181,218	100	%

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

The Company’s significant operations outside the United States include sales, service and application offices in Europe and Asia. For geographical reporting, revenues are attributed to the geographic location in which the product is shipped. Revenue by geographic region is as follows:

	Year Ended December 31,
	2012		2013		2014
Revenues from third parties:
United States	$	42,108	$	40,849	$	60,871
Taiwan	62,239		54,682		49,532
South Korea	33,675		10,704		12,782
Singapore	26,183		17,260		17,807
Austria	11,423		898		752
Japan	16,405		7,326		9,449
Germany	5,393		5,669		9,142
China	12,266		20,061		11,521
Other Europe	8,794		18,789		9,362
Total revenue	$	218,486	$	176,238	$	181,218