Stock Based Compensation

6 Months Ended

Jun. 30, 2017

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

Stock Based Compensation

Stock-Based Compensation

The following costs related to the Company’s stock-based compensation plan are included in the unaudited consolidated statements of income:

	Three months ended June 30,				Six months ended June 30,
	2017		2016		2017		2016
Cost of revenue	$	1,129	$	788	$	2,339	$	2,053
General and administrative expenses	2,344		1,964		4,940		4,336
Selling and marketing expenses	1,634		1,698		3,784		3,870
Total	$	5,107	$	4,450	$	11,063	$	10,259

As of June 30, 2017, the Company had 1,464,838 shares available for grant under the 2015 Amendment and Restatement of the 2006 Omnibus Award Plan.

Stock Options

Stock option activity under the Company’s stock plans is shown below:

	Number of Options		Weighted- Average Exercise Price		Aggregate Intrinsic Value		Weighted- Average Remaining Contractual Life (Years)
Outstanding at December 31, 2016	811,902		$	16.31	$	27,718	2.96
Granted	—		—
Exercised	(136,920	)	12.99
Forfeited	—		—
Outstanding at June 30, 2017	674,982		$	16.98	$	26,060	2.67
Vested and exercisable at June 30, 2017	674,982		$	16.98	$	26,060	2.67

The unrecognized compensation cost for outstanding options as of June 30, 2017 is nil. The Company did not grant any options during the three and six months ended June 30, 2017 and 2016. The total grant date fair value of options vested during the three and six months ended June 30, 2017 was nil and $706, respectively.

Restricted Stock and Restricted Stock Units

Restricted stock and restricted stock unit activity under the Company’s stock plans is shown below:

	Restricted Stock				Restricted Stock Units
	Number		Weighted- Average Fair Value		Number		Weighted- Average Fair Value
Outstanding at December 31, 2016*	246,940		$	42.42	1,256,288		$	37.38
Granted	—		—		387,977		47.94
Vested	(28,694	)	34.89		(397,746	)	35.00
Forfeited	—		—		(68,201	)	40.17
Outstanding at June 30, 2017*	218,246		$	43.41	1,178,318		$	41.50

*     As of June 30, 2017 and December 31, 2016 restricted stock units vested for which the underlying common stock is yet to be issued are 146,112 and 135,054, respectively.

As of June 30, 2017, unrecognized compensation cost of $45,029 is expected to be expensed over a weighted average period of 2.85 years.

Performance Based Stock Awards

Performance restricted stock unit (the "PRSUs") activity under the Company’s stock plans is shown below:

	Revenue Based PRSUs				Market Condition Based PRSUs
	Number		Weighted Avg Fair Value		Number		Weighted Avg Fair Value
Outstanding at December 31, 2016	115,174		$	41.70	215,171		$	47.42
Granted	62,113		47.73		62,100		54.10
Vested	—		—		—		—
Forfeited	(6,960	)	42.97		(6,960	)	58.90
Outstanding at June 30, 2017	170,327		$	43.85	270,311		$	48.66

As of June 30, 2017, unrecognized compensation cost of $10,252 is expected to be expensed over a weighted average period of 1.88 years.