Stock-Based Compensation Plans

Our stock-based award plans are administered by the Compensation Committee of our Board of Directors, which selects persons eligible to receive awards and determines the number, terms, conditions and other provisions of the awards. At December 31, 2019, the total shares available for future grants to employees and directors under existing plans were 4,045,492, which excludes awards we grant in the form of phantom stock unit awards which are expected to be paid in cash. At this time, however, we have temporarily discontinued the grants of any new equity-based awards.

We currently have outstanding stock option and restricted stock awards with vesting based on time of service conditions; restricted stock unit awards with vesting based on time of service conditions, and in certain cases, subject to performance and market conditions; and phantom stock unit awards with vesting based on time of service, performance and market conditions, which are classified as liability awards under ASC Topic 718, Compensation—Stock Compensation since we expect to settle the awards in cash when they become vested.

We recognize compensation cost for our stock-based compensation awards based on the fair value estimated in accordance with ASC Topic 718, Compensation—Stock Compensation, and we recognize forfeitures when they occur. For our awards with graded vesting, we recognize compensation expense on a straight-line basis over the service period for each separately vesting portion of the award as if the award was, in substance, multiple awards.

The following table summarizes the stock-based compensation expense recognized, by award type, and the compensation expense (benefit) recognized for phantom stock unit awards during the years ended December 31, 2019 and 2018 (amounts in thousands):



	Year ended December 31,
	2019			2018
Stock option awards	$	137		$	443
Restricted stock awards	504			460
Restricted stock unit awards	2,129			3,540
	$	2,770		$	4,443

Phantom stock unit awards	$	(112	)	$	47

As of December 31, 2019, the unrecognized compensation cost to be recognized for our outstanding awards totaled $1.5 million. As a result of the filing of our Chapter 11 Cases, we expect that all of these awards will be canceled.

Stock Options

We have outstanding stock option awards which vest, or become exercisable, over a three-year period with exercise prices that approximate the fair market value of our common stock on the date of grant, and that expire ten years after the date of grant. The fair value of each option award is measured on the date of grant using a Black-Scholes option pricing model.

The following table summarizes our stock option activity from December 31, 2018 through December 31, 2019:



	Number of Shares	Weighted-Average Exercise Price Per Share	Weighted-Average Remaining Contract Term in Years	Aggregate Intrinsic Value (in thousands)⁽¹⁾
Outstanding stock options as of December 31, 2018	3,739,910	$5.56
Forfeited	(732,801)	4.33
Outstanding stock options as of December 31, 2019	3,007,109	$5.86	3.8	$	—

Stock options exercisable as of December 31, 2019	2,920,219	$5.85	3.7	$	—

(1) Intrinsic value is the amount by which the market price of our common stock exceeds the exercise price of the stock options.

The following table summarizes our nonvested stock option activity from December 31, 2018 through December 31, 2019:



	Number of Shares	Weighted-Average Grant-Date Fair Value Per Share
Nonvested stock options as of December 31, 2018	480,785	$2.09
Vested	(391,388)	1.59
Forfeited	(2,507)	4.30
Nonvested stock options as of December 31, 2019	86,890	$4.28

Restricted Stock

Our restricted stock awards vest over a one-year period with a fair value based on the closing price of our common stock on the date of the grant. When restricted stock awards are granted, or when restricted stock unit awards are converted to restricted stock, shares of our common stock are considered issued, but subject to certain restrictions.

The following table presents the weighted-average grant-date fair value per share of restricted stock awards granted and the aggregate fair value of restricted stock awards vested during the years ended December 31, 2019 and 2018:



	Year ended December 31,
	2019		2018
Grant-date fair value of awards granted (per share)	$	0.73	$	5.85
Aggregate fair value of awards vested (in thousands)	$	62	$	979

The following table summarizes our restricted stock activity from December 31, 2018 through December 31, 2019:



	Number of Shares	Weighted-Average Grant-Date Fair Value per Share
Nonvested restricted stock as of December 31, 2018	78,632	$5.85
Granted	729,112	0.73
Vested	(78,632)	5.85
Nonvested restricted stock as of December 31, 2019	729,112	$0.73

Restricted Stock Units

We have outstanding restricted stock unit awards with vesting based on time of service conditions only (“time-based RSUs”), and we have outstanding restricted stock unit awards with vesting based on time of service, which are also subject to performance and market conditions (“performance-based RSUs”). Shares of our common stock are issued to recipients of restricted stock units only when they have satisfied the applicable vesting conditions.

Our time-based RSUs generally vest over a three-year period, with fair values based on the closing price of our common stock on the date of grant.

Our performance-based RSUs cliff vest at 39 months from the date of grant and are granted at a target number of issuable shares, for which the final number of shares of common stock is adjusted based on our actual achievement levels that are measured against predetermined performance conditions. The number of shares of common stock awarded will be based upon the Company’s achievement in certain performance conditions, as compared to a predefined peer group, over the performance period, generally three years. The fair value of our performance-based RSUs that are subject to a market condition is measured using a Monte Carlo simulation model, and compensation expense for these awards is reduced only for actual forfeitures; no adjustment to expense is otherwise made regardless of the number of shares issued. The fair value of our performance-based RSUs that are subject to performance conditions is based on the closing price of our common stock on the date of grant, applied to the estimated number of shares that will be awarded, and compensation expense ultimately recognized for these awards will be equal to the fair value of the restricted stock unit award based on the actual outcome of the service and performance conditions. As of December 31, 2019, we estimated that the achievement level for our outstanding performance-based RSUs granted in 2017 will be approximately 75% of the predetermined performance conditions.

The following table summarizes our restricted stock unit activity from December 31, 2018 through December 31, 2019:



	Time-Based Award		Performance-Based Award
	Number of Time-Based Award Units	Weighted-Average Grant-Date Fair Value per Unit	Number of Performance-Based Award Units		Weighted-Average Grant-Date Fair Value per Unit
Nonvested restricted stock units as of December 31, 2018	887,469	$3.80	563,469		$7.73
Granted	870,648	1.38	—		—
Vested	(346,069)	3.58	—		—
Forfeited	(53,891)	2.48	(55,749	)	7.75
Nonvested restricted stock units as of December 31, 2019	1,358,157	$2.36	507,720		$7.73

The following table presents the weighted-average grant-date fair value per share of restricted stock units granted and the aggregate intrinsic value of restricted stock units vested (converted) during the years ended December 31, 2019 and 2018:



	Year ended December 31,
	2019		2018
Time-based RSUs:
Grant-date fair value of awards granted (per share)	$	1.38	$	3.85
Aggregate intrinsic value of awards vested (in thousands)	$	498	$	424
Performance-based RSUs:
Aggregate intrinsic value of awards vested (in thousands)	$	—	$	1,547

Phantom Stock Unit Awards

We have outstanding phantom stock unit awards with vesting based on time of service, performance and market conditions. Time-based phantom stock unit awards, which were granted in 2019, vest annually in thirds over a three-year vesting period. Performance-based phantom stock unit awards, which were granted in 2016, 2018 and 2019, cliff-vest after 39 months from the date of grant, with vesting based on time of service, performance and market conditions. The number of performance-based units ultimately awarded will be based upon the Company’s achievement in certain performance conditions, as compared to a predefined peer group, over the respective three-year performance periods. Each unit awarded will entitle the employee to a cash payment equal to the stock price of our common stock on the date of vesting, subject to an applicable maximum payout feature that is based on a multiple of the grant date stock price.

The fair value of time-based phantom stock unit awards is measured using a Black-Scholes pricing model, and the fair value of performance-based phantom stock unit awards is measured using a Monte Carlo simulation model, with inputs that are defined as Level 3 inputs under ASC Topic 820, Fair Value Measurements and Disclosures.

The following table summarizes the number, weighted-average grant-date fair value, and applicable maximum cash value of the phantom stock unit awards granted during the year ended December 31, 2019 and 2018:



	Year ended December 31,
	2019		2018
Performance-based:
Phantom stock unit awards granted	2,467,776		1,188,216
Weighted-average grant-date fair value (per unit)	$	1.10	$	3.06
Maximum cash value per unit (three times the grant date stock price)	$	4.62	$	9.66
Time-based:
Phantom stock unit awards granted	810,648		—
Weighted-average grant-date fair value (per unit)	$	1.17	$	—
Maximum cash value per unit (three times the grant date stock price)	$	4.62	$	—

The phantom stock unit awards are classified as liability awards under ASC Topic 718, Compensation—Stock Compensation, because we expect to settle the awards in cash when they vest, and are remeasured at fair value at the end of each reporting period until they vest. The change in fair value is recognized as a current period compensation expense in our consolidated statements of operations.Therefore, changes in the inputs used to measure fair value can result in volatility in our compensation expense. This volatility increases as the phantom stock awards approach the vesting date. We estimate that a hypothetical increase of $1 in the market price of our common stock, which was $0.03 as of December 31, 2019, if all other inputs were unchanged, would result in an increase in cumulative compensation expense of $1.4 million, which represents the hypothetical increase in fair value of the liability for the 2018 and 2019 phantom stock unit awards. As of December 31, 2019, we estimate the weighted-average achievement level for our outstanding phantom stock unit awards granted in 2018 and 2019 to be 50%.

In April 2019, we determined that 175% of the target number of phantom stock unit awards granted during 2016 were earned based on the Company’s achievement of the performance measures, as compared to the predefined peer group, which resulted in an aggregate cash payment of $3.5 million to settle these awards.