Convertible Notes - (Tables)

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Convertible Promissory Notes Outstanding

Convertible promissory notes outstanding were as follows:

($ in thousands)	December 31,
	2018			2017
Convertible promissory notes	$	18,003		$	18,003
Debt discount - warrants	(9,598		)	(9,598		)
Debt discount - compound bifurcated derivatives	(1,267		)	(1,267		)
Debt discount - beneficial conversion feature	(7,138		)	(7,138		)
Convertible promissory notes, net	$	—		$	—

Estimated Fair Value of Compounded Bifurcated Derivative

Significant inputs and assumptions used in the binomial lattice model for the derivative liability are as follows:

($ in thousands except per share data)	December 31, 2018			December 31, 2017
Calculated aggregate value	$	1,474		$	3,136
Closing price per share of common stock	$	1.50		$	3.20
Contractual remaining term	7 years, 8 months			8 years, 8 months
Contractual interest rate	4.0		%	4.0		%
Volume-weighted average conversion rate	$	17.04667		$	17.04667
Risk-free interest rate (term structure)	2.44% - 2.69%			1.28% - 2.40%
Dividend yield	—			—
Credit Rating	CC			CC
Credit Spread	31.77		%	36.98		%
Volatility	87.5		%	99.0		%