Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2019

Schedule of Stock Based Compensation Expense

Stock-based compensation expense was as follows for the three and nine months ended September 30, 2019 and 2018 (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2019		2018		2019		2018
Restricted stock units	$	445	$	1,026	$	3,773	$	3,164
Performance units		374		1,047		3,364		2,685
Restricted and unrestricted stock		242		98		477		282
Total expense	$	1,061	$	2,171	$	7,614	$	6,131

Summary of Employee Restricted Stock Unit Awards Activity

A summary of employee restricted stock unit awards activity during the nine months ended September 30, 2019 is as follows:

	Number of shares			Weighted average grant date fair value		Aggregate intrinsic value (in thousands)
Total awarded and unvested, December 31, 2018		233,960		$	29.27	$	3,685
Granted		407,714			6.46
Vested		(212,140	)		28.71
Forfeited		(485	)		31.78
Total awarded and unvested, September 30, 2019		429,049		$	7.86	$	1,622

Summary of Performance Stock Unit Awards Activity

A summary of performance stock unit awards activity during the nine months ended September 30, 2019 is as follows

	Number of shares			Weighted average grant date fair value		Aggregate intrinsic value (in thousands)
Total awarded and unvested, December 31, 2018		346,589		$	27.68	$	716
Granted		255,419			7.25
Vested		(270,068	)		27.57
Forfeited		(16,483	)		24.60
Total awarded and unvested, September 30, 2019		315,457		$	11.39	$	—

Performance Units [Member]

Assumptions Used to Determine Fair Value of Performance Stock Units Granted

The following table presents the assumptions used to determine the fair value for performance stock units granted during the nine months ended September 30, 2019 and 2018:

	Nine Months Ended September 30,
	2019			2018
Volatility		65.10	%		89.70	%
Risk-free interest rate		1.83	%		2.37	%