Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2019

Share-based Payment Arrangement [Abstract]

Summary of stock option activity

A summary of stock option activity during the six months ended June 30, 2019 is as follows (in thousands, except for per share amounts):

	Shares		Weighted- Average Exercise Price (in dollars per share)		Weighted- Average Contractual Life (in years)	Aggregate Intrinsic Value
Options outstanding at December 31, 2018	5,463		$	36.88
Granted	925		19.34
Exercised	(341	)	8.40
Canceled	(454	)	34.23
Expired	(429	)	39.66
Options outstanding at June 30, 2019	5,164		$	35.63	7.13	$	9,593
Options exercisable at June 30, 2019	2,957		$	40.16	5.86	$	4,252

Summary of restricted stock units activity

A summary of RSU activity during the six months ended June 30, 2019 is as follows (in thousands, except for per share amounts):

	RSUs		Weighted- Average Grant Date Fair Value  (in dollars  per share)
RSUs Outstanding at December 31, 2018	227		$	37.69
Granted	613		20.04
Vested	(75	)	38.59
Forfeited	(81	)	26.86
RSUs Outstanding at June 30, 2019	684		$	23.02

A summary of PSU activity during the six months ended June 30, 2019 is as follows (in thousands, except for per share amounts):

	PSUs	Weighted- Average Grant Date Fair Value  (in dollars  per share)
PSUs Outstanding at December 31, 2018	—	$	—
Granted	79	19.20
Vested	—	—
Forfeited	—	—
PSUs Outstanding at June 30, 2019	79	$	19.20