Stock Based Compensation (Tables)

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



	Three months ended March 31,
	2017		2016
Cost of revenue	$	1,210	$	1,265
General and administrative expenses	2,596		2,372
Selling and marketing expenses	2,150		2,172
Total	$	5,956	$	5,809

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	(7,970	)	23.99
Forfeited	—		—
Outstanding at March 31, 2017	803,932		$	16.23	$	25,031	2.70
Vested and exercisable at March 31, 2017	803,932		$	16.23	$	25,031	2.70

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



	Restricted Stock				Restricted Stock Units
	Number		Weighted- Average Intrinsic Value		Number		Weighted- Average Intrinsic Value
Outstanding at December 31, 2016*	246,940		$	42.42	1,256,288		$	37.38
Granted	—		—		372,019		47.71
Vested	(24,426	)	35.91		(371,374	)	34.56
Forfeited	—		—		(13,890	)	41.66
Outstanding at March 31, 2017*	222,514		$	43.13	1,243,043		$	41.27

* As of March 31, 2017 and December 31, 2016 restricted stock units vested for which the underlying common stock is yet to be issued are 138,328 and 135,054, respectively.

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	61,123	47.73		61,111	54.10
Vested	—	—		—	—
Forfeited	—	—		—	—
Outstanding at March 31, 2017	176,297	$	43.79	276,282	$	48.90