Share-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Share-Based Compensation Expense

Total share-based compensation expense, net of estimated forfeitures, recognized using the straight-line attribution method in the consolidated statements of operations is as follows:

	Three months ended June 30,				Six months ended June 30,
($ in thousands)	2015		2014		2015		2014
Stock option compensation expense for employees and directors	$	804	$	436	$	1,044	$	736
Equity awards for non-employees issued for services	—		—		—		3
Total stock-based compensation expense	$	804	$	436	$	1,044	$	739

Summary of Stock Option Activity

($ in thousands except share and per share data)	Number of shares		Weighted- average exercise price		Weighted-average remaining contractual term (in years)	Aggregate intrinsic value ($ in thousands)
Outstanding at December 31, 2014	2,086,450		$	7.43	8 years	$	—
Granted	1,333,614		4.45
Exercised	(56,250	)	4.53
Forfeited	(115,000	)	3.91
Expired	(12,000	)	10.50
Outstanding at June 30, 2015	3,236,814		$	6.37	8 years, 5 months	$	2,910
Exercisable at June 30, 2015	1,353,075		$	9.39	7 years, 4 months	$	810

Details of Fair Value Option Award

The fair market value of these options was computed using the Black-Scholes option-pricing model with the following key weighted average assumptions for the six months ended as of the dates indicated:

	June 30, 2015		June 30, 2014
Expected life	6 years, 1 month		6 years, 3 months
Interest rate	1.56	%	1.97	%
Dividend yield	—		—
Volatility	103.3	%	70.4	%