Segment Reporting and Geographic Information - (Tables)

12 Months Ended

Dec. 31, 2018

Segment Reporting And Geographic Information [Abstract]

Schedule of Revenue from External Customers by Products and Services

The following table lists the different sources of revenue:

	Year Ended December 31,
	2018				2017				2016
Systems and Software:
Process control	$	190,098	70	%	$	177,177	70	%	$	146,652	63	%
Lithography		14,975	5	%		14,234	5	%		18,949	8	%
Software licensing, support and maintenance		29,168	11	%		25,473	10	%		29,795	13	%
Parts		28,658	10	%		27,143	11	%		25,343	11	%
Services		10,885	4	%		11,071	4	%		12,041	5	%
Total revenue	$	273,784	100	%	$	255,098	100	%	$	232,780	100	%

Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area

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

	Year Ended December 31,
	2018		2017		2016
Revenue from third parties:
United States	$	43,944	$	36,104	$	30,876
Taiwan		45,312		63,079		68,211
South Korea		51,750		44,180		15,556
Singapore		14,371		12,775		35,517
Austria		719		2,601		2,049
Japan		22,361		18,943		11,875
Germany		14,913		15,580		9,759
China		63,243		35,925		33,720
Other Europe		11,541		21,167		18,720
Other Asia		5,630		4,744		6,497
Total revenue	$	273,784	$	255,098	$	232,780