Stock-Based Compensation - (Tables)

6 Months Ended

Jun. 30, 2019

A summary of the stock option activity for the six months ended June 30, 2019 is presented below.



	Number of Shares		Weighted Average Exercise Price
Outstanding at January 1, 2019	4,557,186		$	5.14
Granted	—		$	—
Exercised	(189,742	)	$	5.67
Forfeited	(3,045	)	$	14.00
Expired	—		$	—
Outstanding at June 30, 2019	4,364,399		$	5.11
Exercisable at June 30, 2019	3,989,591		$	4.28

The following table summarizes RSUs activity during the six months ended June 30, 2019:



	Number of Shares		Weighted Average Grant Date Fair Value
Outstanding at January 1, 2019	473,505		$	16.52
Granted	373,479		$	20.99
Vested	(171,451	)	$	16.10
Forfeited	(1,926	)	$	13.25
Expired	—		$	—
Outstanding at June 30, 2019	673,607		$	19.11

The following table summarizes information about PSUs activity during the six months ended June 30, 2019:



Period Granted	Target Shares Outstanding at January 1, 2019	Target Shares Granted	Target Shares Vested	Target Shares Forfeited	Target Shares Outstanding at June 30, 2019	Weighted Average Grant Date Fair Value per Share
2017	169,635	—	—	—	169,635	$	10.73
2018	178,975	—	—	—	178,975	$	27.51
2019	—	199,413	—	—	199,413	$	34.82
Total	348,610	199,413	—	—	548,023	$	24.98