Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2017

Summary of Weighted Average Assumptions Used for Calculating Per Share Weighted Average Fair Value of Stock Options

We calculated the fair value of each option award on the date of grant using the Black-Scholes option pricing model. There were no stock options granted during 2017. The per share weighted average fair value of the stock options granted to employees during 2016 was $2.63. The following weighted average assumptions were used for each respective period:

	2016
Expected term		7
Dividends to common stockholders	None
Risk-free interest rate	1.45%
Expected volatility		115.39

Summary of Stock Options

Stock options have only been granted to employees or directors. Our stock options have various vesting schedules and are subject to the employees’ continuing service. A summary of the status of our stock options, as of December 31, 2017 and 2016, and changes during the years ended December 31, 2017 and 2016, is presented below (in thousands, except per share data and contractual life):

								Weighted
				Weighted				Average
				Average		Aggregate		Remaining
				Exercise		Intrinsic		Contractual
	Shares			Price		Value		Life (Years)
Outstanding at December 31, 2015		128			11.25
Granted		315			3.06
Exercised		—			—
Forfeited		(35	)		18.31
Outstanding at December 31, 2016		408		$	4.32
Granted		—			—
Exercised		—			—
Forfeited		(15	)		26.07
Outstanding at December 31, 2017		393		$	3.48	$	—		7.5
Exercisable at December 31, 2017		343		$	3.56	$	—		7.0

Summary of Stock Options Outstanding and Exercisable

The following table summarizes information about our stock options outstanding and exercisable at December 31, 2017 (in thousands, except per share data and contractual life):

							Weighted
					Weighted		Average				Weighted
					Average		Remaining				Average
	Vested		Unvested		Exercise		Contractual		Options		Exercise
Range of Exercise Prices	Options		Options		Price		Life (Years)		Exercisable		Price
$1.03 - 2.99		45		50	$	2.68		8.4		45	$	2.33
3.00 - 4.99		273		—		3.21		7.6		273		3.21
5.00 - 9.99		20		—		7.50		2.3		20		7.50
10.00 - 17.90		5		—		17.90		2.4		5		17.90
		343		50	$	3.48		7.5		343	$	3.56