Balance Sheet Components (Tables)

3 Months Ended

Mar. 31, 2019

Balance Sheet Related Disclosures [Abstract]

Schedule of Property and Equipment, Net

Property and equipment consisted of the following (in thousands): 

	March 31, 2019			December 31, 2018
Prototype	$	12,247		$	12,425
Machinery and equipment		13,871			12,654
Leasehold improvements		4,621			4,600
Furniture and fixtures		665			636
Software		1,296			1,250
Construction in progress		1,216			148
Property and equipment, gross		33,916			31,713
Less: accumulated depreciation and amortization		(18,637	)		(17,755	)
Property and equipment, net	$	15,279		$	13,958

Schedule of Accrued Liabilities

Accrued liabilities consisted of the following (in thousands):

	March 31, 2019		December 31, 2018
Accrued payroll and related benefits	$	5,828	$	5,047
Accrued accounts payable		3,736		3,626
Payroll withholding tax, sales and other tax payable		439		782
Accrued legal, accounting and professional fees		721		360
Product upgrade reserve		4,964		—
Other		519		168
Total accrued liabilities	$	16,207	$	9,983

Schedule of Deferred Revenue

Deferred revenue consisted of the following (in thousands):

	March 31, 2019			December 31, 2018
Deferred revenue:
Product	$	5,424		$	9,623
Service		7,618			6,981
Distribution rights		2,752			2,871
Total deferred revenue		15,794			19,475
Less: current portion of deferred revenue		(10,287	)		(13,731	)
Noncurrent portion of deferred revenue	$	5,507		$	5,744

Schedule of Other Long Term Liabilities

Other Long-Term Liabilities

	March 31, 2019		December 31, 2018
Accrued interest, noncurrent portion	$	104	$	—
Deferred rent, noncurrent portion		—		628
Other		199		192
Total other-long term liabilities	$	303	$	820