Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2019

Stockholders' Equity Note [Abstract]

Share-based Compensation, Stock Options, Activity

Stock option activity for options granted under the 2017 Plan during the three months ended March 31, 2019 is presented in the table below:

	Number of Shares Available		Number of Options Outstanding		Weighted-average Exercise Price		Weighted-average Remaining Contractual Term (years)	Aggregate Intrinsic Value
Balance at December 31, 2018	157,881		343,550		$	28.97	8.95	$	840
Annual additional options authorized	153,814		—		—
Granted	(89,700	)	89,700		$	13.76
Exercised	—		—		—
Forfeited	1,836		(1,836	)	$	16.64
Balance at March 31, 2019	223,831		431,414		$	25.86	8.92	$	—

Stock option activity for the Pre-2017 Non-Qualified Stock Options for the three months ended March 31, 2019 is presented in the table below:

	Number of Shares		Weighted- average Exercise Price		Weighted- average Remaining Contractual Term (years)	Aggregate Intrinsic Value (in Thousands)
Outstanding at December 31, 2018	2,885,500		$	7.30	6.04	$	20,633,100
Exercised	(80,000	)	7.52
Forfeited	(4,865	)	10.00
Outstanding at March 31, 2019	2,800,635		$	7.29	5.77	$	16,358,456
Exercisable at March 31, 2019	2,695,766		$	7.21	5.76	$	15,932,550

Warrant activity for the three months ended March 31, 2019 is presented in the table below:

	Number of Shares	Weighted- average Exercise Price		Weighted- average Remaining Contractual Term (years)	Aggregate Intrinsic Value (in Thousands)
Outstanding at December 31, 2018	353,610	$	9.78	4.36	$	1,181
Exercised	—	$	—
Outstanding at March 31, 2019	353,610	$	9.78	4.36	$	1,181
Exercisable at March 31, 2019	353,610	$	9.78	4.36	$	1,181

Schedule of Nonvested Share Activity

A summary of the status of the Company’s non-vested Pre-2017 Non-Qualified Stock Options as of March 31, 2019 is presented below:

	Number of Options	Weighted Average Grant Date Fair Value
Non-vested at March 31, 2019	109,734	$	7.76

A summary of the status of the Company’s non-vested options granted under the 2017 Plan as of March 31, 2019 is presented in the following table:

	Number of Shares		Weighted Average Grant Date Fair Value Per Share
Balance at March 31, 2019	431,414		$	25.34
Vested	(106,278	)	30.53
Non-vested at March 31, 2019	325,136		$	23.64

Schedule of Assumptions Used in the Valuation

The assumptions used in the valuation of options granted under the 2017 Plan during the three months ended March 31, 2019 are as follows:

	For the Three Months Ended March 31, 2019
Market value of stock on measurement date	$13.61 to $14.62
Risk-free interest rate	2.41% to 2.57%
Dividend yield	—
Volatility factor	121%
Term	6.25 Years