15.	Restricted Stock Units

In 2015 and 2016, the Company issued Restricted Stock Units (“RSUs”) to certain employees which vest over three years. By their terms, the RSUs become immediately vested upon the earlier of (i) a change of control and (ii) defined vesting dates, subject to the continuous service with the Company at the applicable vesting event. When vested, the RSUs represent the right to be issued the number of shares of the Company’s common stock that is equal to the number of RSUs granted. The fair value of each RSU is estimated based upon the closing price of the Company’s common stock on the grant date. Share-based compensation expense related to RSUs is recognized over the requisite service period as adjusted for estimated forfeitures.

The following is a summary of the RSU activity for the years ended December 31, 2016, 2015 and 2014:

				Weighted
	Number of			Average
	Restricted			Grant
	Stock Units			Date Fair
	Outstanding			Value
Unvested, December 31, 2013		210,000		$	7.19
Granted		—			—
Vested		(70,000	)		7.19
Unvested, December 31, 2014		140,000		$	7.19
Granted		380,000			2.94
Vested		(70,000	)		7.19
Forfeited		(27,500	)		2.94
Unvested, December 31, 2015		422,500		$	3.64
Granted		660,331			3.74
Vested		(187,503	)		4.53
Unvested, December 31, 2016		895,328		$	3.53

As of December 31, 2016, 2015 and 2014, the Company recorded approximately $1,463,000, $816,000 and $503,000, respectively, in compensation expense for the RSUs. As of December 31, 2016, the unrecognized stock-based compensation expense related to unvested RSUs was approximately $2.1 million, which is expected to be recognized over a weighted average period of approximately 1.9 years. No restricted stock units were granted in 2014. The weighted average grant date fair value of the RSUs granted in 2015 was $2.94. The weighted average grant date fair value of the RSUs granted in 2016 was $3.74.