Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2018

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

Summary of stock option activity

A summary of stock option activity during the six months ended June 30, 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	1,098		37.43
Exercised	(445	)	16.43
Canceled	(265	)	43.90
Expired	(307	)	51.53
Options outstanding at June 30, 2018	5,729		$	38.91	7.67	$	13,536
Options exercisable at June 30, 2018	2,965		$	36.27	6.59	$	13,280

Summary of restricted stock units activity

A summary of RSU activity during the six months ended June 30, 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	(24	)	41.37
Forfeited	(48	)	38.07
RSUs Outstanding at June 30, 2018	296		$	36.93