Details of Certain Consolidated Balance Sheet Accounts (Tables)

12 Months Ended

Dec. 31, 2017

Balance Sheet Related Disclosures [Abstract]

Schedule of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets (in thousands):

	December 31,
	2016		2017
Prepaid software and licenses	$	286	$	407
Prepaid insurance		25		211
Other prepaid expenses		171		137
Other		85		84
	$	567	$	839

Schedule of Property and Equipment, Net

Property and equipment, net (in thousands):

	December 31,
	2016			2017
Deployed equipment	$	13,240		$	17,091
Computer equipment		912			1,123
Software		202			312
Furniture and fixtures		151			165
Leasehold improvements		185			202
Construction in progress		2,084			1,456
	$	16,774		$	20,349
Accumulated depreciation and amortization		(7,815	)		(8,753	)
	$	8,959		$	11,596

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities (in thousands):

	December 31,
	2016		2017
Payroll liabilities	$	1,146	$	1,697
Accrued employee paid time off		372		469
Accrued commissions		51		199
Accrued ESPP		—		115
Accrued interest		123		—
Royalties payable		225		125
Professional fees		76		328
Sales/ use tax payable		167		406
Other		199		476
	$	2,359	$	3,815