Details of Certain Consolidated Balance Sheet Accounts - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accrued Expenses And Other Current Liabilities [Abstract]
Payroll liabilities	$ 1,697	$ 1,146
Accrued employee paid time off	469	372
Accrued commissions	199	51
Accrued ESPP	115
Accrued interest		123
Royalties payable	125	225
Professional fees	328	76
Sales/ use tax payable	406	167
Other	476	199
Accrued expenses and other current liabilities	$ 3,815	$ 2,359