Condensed Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Property and equipment, accumulated depreciation	$ 481	$ 455
Unamortized deferred financing cost, net	50	63
Unamortized debt discount	806	993
Obligation under capital lease of current maturities	$ 10	$ 10
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized	200,000,000	200,000,000
Common stock, issued	78,371,119	66,405,180
Common stock, outstanding	78,371,119	66,405,180