Note 10—Stock-Based Compensation

The Company is authorized to grant up to 16,000,000 shares of common stock under its 2014 Long-Term Incentive Plan (the “Plan”). The Plan allows stock-based compensation awards to be granted in a variety of forms, including stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, dividend equivalent rights, qualified performance-based awards and other types of awards. The terms and conditions of the awards granted are established by the Compensation Committee of the Company’s Board of Directors. A total of 8,019,938 shares are available for future grant under the Plan as of December 31, 2016.

Our stock based compensation expense is as follows for the years ended December 31, 2016, 2015, and 2014 (in thousands):

	Year Ended December 31,
	2016			2015		2014
Restricted stock units	$	4,006		$	2,408	$	—
Performance units		1,922			1,297		—
Restricted stock issued to directors		556			827		138
Incentive units		(268	)		103		118
Total expense	$	6,216		$	4,635	$	256

Restricted Stock Units

Restricted stock unit awards vest subject to the satisfaction of service requirements. The Company recognizes expense related to restricted stock and restricted stock unit awards on a straight-line basis over the requisite service period, which is three years. The grant date fair values of these awards are determined based on the closing price of the Company’s common stock on the date of the grant. As of December 31, 2016, there was $5.0 million of total unrecognized compensation cost related to restricted stock units. The weighted average period for the shares to vest is approximately 1 year.

A summary of restricted stock unit awards activity during the year ended December 31, 2016 is as follows:

	Number of shares			Weighted average grant date fair value		Aggregate intrinsic value (in thousands)
Total awarded and unvested, December 31, 2015		1,000,052		$	7.07	$	1,820
Granted		3,751,931			1.36
Vested		(340,879	)		7.13
Forfeited		(67,522	)		7.13
Total awarded and unvested, December 31, 2016		4,343,582		$	2.14	$	11,597

Performance Units

Performance unit awards vest subject to the satisfaction of a three-year service requirement and based on Total Shareholder Return (“TSR”), as compared to an industry peer group over that same period. The performance unit awards are measured at the grant date at fair value using a Monte Carlo valuation method. As of December 31, 2016, there was $3.1 million of total unrecognized compensation cost related to performance units. The weighted average period for the shares to vest is approximately 2 years.

A summary of performance stock unit awards activity during the year ended December 31, 2016 is as follows:

	Number of shares		Weighted average grant date fair value		Aggregate intrinsic value (in thousands)
Total awarded and unvested, December 31, 2015		458,656	$	8.77	$	417
Granted		1,469,346		1.60
Vested		—		—
Forfeited		—		—
Total awarded and unvested, December 31, 2016		1,928,002	$	3.31	$	5,148

The determination of the fair value of the performance unit awards noted above uses significant Level 3 assumptions in the fair value hierarchy including an estimate of the timing of forfeitures, the risk free rate and a volatility estimate tied to the Company’s public peer group.

Restricted Stock Issued to Directors

On October 7, 2014, the Company issued an aggregate of 31,115 restricted shares of common stock to its seven non-employee members of its Board of Directors, which became fully vested on June 25, 2015. For the years ended December 31, 2015 and 2014, the Company recognized expense of approximately $0.3 million and $0.1 million, respectively, related to these awards.

On May 11, 2015, the Company issued an aggregate of 132,496 restricted shares of common stock to its seven non-employee members of its Board of Directors, which became fully vested on May 11, 2016. For the years ended December 31, 2016 and 2015, the Company recognized expense of approximately $0.3 million and $0.6 million, respectively, related to these awards.

On May 18, 2016, the Company issued an aggregate of 149,448 restricted shares of common stock to its three non-employee members of its Board of Directors that are not affiliated with the Company’s controlling stockholder, which are scheduled to fully vest on May 18, 2017. For the year ended December 31, 2016, the Company recognized expense of approximately $0.3 million related to these awards. As of December 31, 2016, there was approximately $0.2 million of total unrecognized compensation cost related to outstanding restricted stock issued to the Company’s Directors.