Accrued Liabilities (Tables)

12 Months Ended

Dec. 31, 2018

Payables and Accruals [Abstract]

Accrued Liabilities Schedule

Accrued liabilities consist of the following:

	As of December 31,
	2018		2017
Accrued compensation and benefits	$	17,745	$	16,144
Accrued warranties	2,571		2,628
Professional and legal fees	2,154		1,541
Taxes other than income	3,550		3,787
General services administration contract contingent liability (see Note 13)	5,267		—
Other accrued liabilities	5,040		3,262
	$	36,327	$	27,362

Schedule of Activity Related to Accrued Warranties

Activity related to accrued warranties was as follows:

	Years ended December 31,
	2018			2017			2016
Balance, beginning of year	$	2,628		$	2,594		$	2,309
Provision for warranty expense	4,096			4,045			3,544
Fulfillment of warranty obligations	(4,153		)	(4,011		)	(3,259		)
Balance, end of year	$	2,571		$	2,628		$	2,594