Stock-based Compensation and Benefits - (Tables)

9 Months Ended

Sep. 30, 2017

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

Summary of outstanding stock options

The following table summarizes stock option activity for the nine months ended September 30, 2017:

				Weighted
				average
		Weighted		remaining
		average		contractual	Aggregate
		exercise		term in	intrinsic
	Options	price		years	value
Outstanding at December 31, 2016	2,185,922	$	19.81	4.85	$	7,753
Granted	100,401		33.98
Exercised	(598,728)		19.90
Forfeited	(26,455)		22.11
Outstanding at September 30, 2017	1,661,140	$	20.62	4.25	$	25,042
Options exercisable at September 30, 2017	1,425,900	$	19.82	3.52	$	22,829
Options vested and expected to vest	1,644,451	$	20.55	4.21	$	24,905

Summary of Restricted Stock Activity

The following table summarizes restricted stock and performance stock activity during the nine months ended September 30, 2017:

		Weighted				Weighted
	Restricted	average grant-		Performance		average grant-
	shares	date fair value		stock units		date fair value
Unvested at December 31, 2016	499,271	$	15.82	85,295	$	18.22
Granted	66,471		33.43	49,758		33.22
Vested	(300,448)		15.31	—		—
Forfeited	(18,817)		17.53	(9,278)		21.46
Unvested at September 30, 2017	246,477	$	20.41	125,775	$	23.91