Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2019

Stock-based Compensation

Summary of the stock-based compensation activity

	Quarter ended September 30,				Nine months ended September 30,
	2019		2018		2019		2018
	(in thousands)
Grants:
Units:
Performance-based RSUs		—		—		665		524
Stock options		—		—		344		674
Time-based RSUs		4		5		334		321
Grant date fair value:
Performance-based RSUs	$	—	$	—	$	15,253	$	12,791
Stock options		—		—		2,965		6,147
Time-based RSUs		102		100		7,647		7,803
Total	$	102	$	100	$	25,865	$	26,741
Vestings and exercises:
Performance-based RSUs vested		—		—		648		774
Stock options exercised		127		55		245		285
Time-based RSUs vested		3		1		294		245
Compensation expense	$	8,941	$	8,532	$	19,124	$	20,766