Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Schedule of Disaggregation of Revenue

The following table presents the Company’s revenue disaggregated by revenue source:

	Year Ended December 31,
	2018		2017		2016
Systems	$	205,073	$	191,411	$	165,601
Software licensing, support and maintenance		29,168		25,473		29,795
Parts		28,658		27,143		25,343
Services		10,885		11,071		12,041
Total revenue	$	273,784	$	255,098	$	232,780

The following table represents a disaggregation of revenue by timing of revenue:

	Year Ended December 31,
	2018
Point-in-time	$	257,124
Over-time		16,660
Total revenue	$	273,784

Schedule of Changes in Deferred Revenue

Changes in deferred revenue were as follows:

	Year Ended December 31,
	2018
Balance, beginning of the period	$	7,206
Deferral of revenue		19,326
Recognition of deferred revenue		(18,452	)
Balance, ending of the period	$	8,080

Forward Contracts and Related Fair Values

The dollar equivalent of the U.S. dollar forward contracts and related fair values as of December 31, 2018 and 2017 were as follows:

	December 31,
	2018			2017
Notional amount		6,746			8,417
Fair value of asset (liability)		(32	)		45