Revenue (Tables)

12 Months Ended

Dec. 31, 2019

Revenue from Contract with Customer [Abstract]

Schedule of Sales by End Market

The following tables represent a disaggregation of revenue from contracts with customers for the periods presented (in thousands):

Sales by End Market

	Year Ended December 31,
	2019		2018		2017
Industrial	$	76,668	$	82,763	$	56,622
Microfabrication	57,153		74,108		60,886
Aerospace and Defense	42,798		34,488		21,072
	$	176,619	$	191,359	$	138,580

Schedule of Sales by Geography

Sales by Geography

	Year Ended December 31,
	2019		2018		2017
North America	$	67,511	$	70,694	$	46,489
China	64,134		70,196		55,344
Rest of World	44,974		50,469		36,747
	$	176,619	$	191,359	$	138,580

Schedule of Sales by Timing of Revenue

Sales by Timing of Revenue

	Year Ended December 31,
	2019		2018		2017
Point in time	$	168,699	$	185,989	$	137,528
Over time	7,920		5,370		1,052
	$	176,619	$	191,359	$	138,580

Schedule of Contract Assets and Liabilities

The Company's contract assets and liabilities are as follows (in thousands):

	Balance Sheet	As of December 31,
	Classification	2019		2018
Contract assets	Prepaid expenses and other current assets	$	2,449	$	331
Contract liabilities	Deferred revenue	881		1,240