Accrued Expenses and Other Liabilities - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Accrued Expenses [Line Items]
Deferred revenue	$ 393	$ 25
Super G Warrant liability	165	0
Accrued compensation costs	129	133
Other accrued expenses	80	6
Accrued communication costs	78	111
Accrued dividends on Series A-2 Preferred Stock	59	47
Deferred rent expense	46	71
Accrued professional fees	35	68
Accrued interest expense	18	658
Customer deposits	0	93
Accrued expenses and other liabilities	1,003	1,212
Series A-2 Preferred Stock
Schedule Of Accrued Expenses [Line Items]
Accrued dividends on Series A-2 Preferred Stock	$ 59	$ 47