Stock Options And Employee Stock Purchase Plan (Tables)

3 Months Ended

Mar. 31, 2016

The following table represents stock option activity for the three months ended March 31, 2016:



	Number of Shares		Weighted- Average Exercise Price		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Outstanding at January 1, 2016	566,428		$	29.74
Granted	—		—
Exercised	(51,458	)	25.51
Canceled	(9,700	)	26.92
Outstanding at March 31, 2016	505,270		$	30.23	4.2	$	16,199,622
Exercisable at March 31, 2016	409,655		$	24.76	3.3	$	15,082,140
Vested and expected to vest at March 31, 2016	486,871		$	29.01	4.0	$	16,123,590

Restricted stock award activity for the three months ended March 31, 2016 is set forth below:



	Shares		Weighted-Average Grant-Date Fair Value
Nonvested at January 1, 2016	704,804		$	39.08
Granted	18,000		63.51
Vested	(26,943	)	34.97
Canceled	(4,500	)	47.68
Nonvested at March 31, 2016	691,361		$	39.82

Restricted stock unit award activity for the three months ended March 31, 2016 is set forth below:



	Number of Shares		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Outstanding at January 1, 2016	56,245
Granted	1,250
Vested	(6,575	)
Canceled	—
Outstanding at March 31, 2016	50,920		1.8	$	3,135,654
Vested and expected to vest at March 31, 2016	39,014		1.6	$	2,402,479