Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of stock option activity

A summary of stock option activity during the three months ended March 31, 2018 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, 2017	5,648		$	37.71
Granted	1,020		37.79
Exercised	(414	)	15.85
Canceled	(107	)	42.70
Expired	(261	)	51.38
Options outstanding at March 31, 2018	5,886		$	38.58	7.96	$	23,712
Options exercisable at March 31, 2018	2,799		$	36.12	6.84	$	20,508

Summary of restricted stock units activity

A summary of RSU activity during the three months ended March 31, 2018 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, 2017	147		$	36.69
Granted	221		37.83
Vested	(16	)	45.65
Forfeited	(15	)	40.09
RSUs Outstanding at March 31, 2018	337		$	36.86