Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2020

Stock-based Compensation

Summary of the stock-based compensation activity

	Quarter ended March 31,
	2020		2019
	(in thousands)
Grants:
Units:
Performance-based RSUs		422		665
Stock options		273		344
Time-based RSUs		304		330
Grant date fair value:
Performance-based RSUs	$	14,768	$	15,253
Stock options		2,770		2,965
Time-based RSUs		10,662		7,545
Total	$	28,200	$	25,763
Vestings and exercises:
Performance-based RSUs vested		603		648
Stock options exercised		180		89
Time-based RSUs vested		348		291
Compensation expense	$	12,368	$	4,531