Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2017

Our stock-based compensation expense was as follows for the three and six months ended June 30, 2017 and 2016 (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2017		2016		2017		2016
Restricted stock units	$	1,344	$	1,388	$	2,591	$	2,243
Performance units		907		677		1,641		1,057
Restricted stock issued to directors		97		142		197		353
Incentive units		—		19		—		48
Total expense	$	2,348	$	2,226	$	4,429	$	3,701

A summary of restricted stock unit awards activity during the six months ended June 30, 2017 is as follows:

	Number of shares			Weighted average grant date fair value		Aggregate intrinsic value (in thousands)
Total awarded and unvested, December 31, 2016		4,343,582		$	2.14	$	11,597
Granted		2,667,893			2.12
Vested		(2,911,900	)		1.65
Forfeited		(47,812	)		2.50
Total awarded and unvested, June 30, 2017		4,051,763		$	2.47	$	11,588

A summary of performance stock unit awards activity during the six months ended June 30, 2017 is as follows

	Number of shares			Weighted average grant date fair value		Aggregate intrinsic value (in thousands)
Total awarded and unvested, December 31, 2016		1,928,002		$	3.31	$	5,148
Granted		2,564,523			1.94
Vested		—			—
Forfeited		(59,788	)		3.04
Total awarded and unvested, June 30, 2017		4,432,737		$	2.52	$	11,537