Details of Certain Consolidated Balance Sheet Accounts - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Prepaid Expense And Other Assets Current [Abstract]
Prepaid software and licenses	$ 407	$ 286
Prepaid insurance	211	25
Other prepaid expenses	137	171
Other	84	85
Total	$ 839	$ 567