Accrued Expenses and Other Liabilities - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Accrued Expenses, Current [Abstract]
Accrued compensation costs	$ 188	$ 129
Other accrued expenses	134	257
Accrued dividends	65	59
Deferred revenue	60	393
Super G Warrant liability	0	165
Accrued expenses and other liabilities	$ 447	$ 1,003