(9) Stock Based Compensation

The Company recognizes compensation costs for stock options awarded to employees based on their grant-date fair value. The value of each stock option is estimated on the date of grant using the Black-Scholes option-pricing model. The weighted-average fair value per share for the stock options granted to employees during the nine months ended September 30, 2015 was $10.59. The weighted-average fair value per share for the stock options granted to employees during the nine months ended September 30, 2014 was $6.49.

For the three months ended September 30, 2015 and 2014, the Company recorded $776 and $636, respectively, in selling, general and administrative expenses for stock options. For the nine months ended September 30, 2015 and 2014, the Company recorded $2,114 and $1,785, respectively, in selling, general and administrative expenses for stock options. As of September 30, 2015, total compensation cost related to unvested stock options not yet recognized was $5,079. The cost will be amortized on a straight-line basis over the remaining weighted-average vesting period of 2.2 years.

The following table is a summary of the Company’s stock options:

Options	Number of Shares			Weighted Average Exercise Price
Outstanding at December 31, 2014		2,070,672		$	12.08
Granted		29,500		$	23.45
Exercised		(212,276	)	$	7.25
Forfeited or expired		(80,375	)	$	14.48
Outstanding at March 31, 2015		1,807,521		$	12.72
Granted		23,818		$	41.11
Exercised		(62,625	)	$	5.68
Outstanding at June 30, 2015		1,768,714		$	13.35
Exercised		(157,850	)	$	6.74
Outstanding at September 30, 2015		1,610,864		$	14.00
Exercisable at September 30, 2015		577,796		$	10.16

The aggregate intrinsic values for all stock options exercised for the three and nine months ended September 30, 2015 were $6,807 and $14,229, respectively. The aggregate intrinsic values for all stock options exercised for the three and nine months ended September 30, 2014 were $5,234 and $7,641, respectively. The aggregate intrinsic values for all stock options outstanding and exercisable as of September 30, 2015 were $41,401 and $17,054, respectively.

The following table is a summary of the Company’s nonvested stock options and restricted stock:

	Nonvested Stock Options					Nonvested Restricted Stock
	Number of Shares			Weighted-Average Grant-Date Fair Value		Number of Shares		Weighted-Average Grant-Date Fair Value

Nonvested at December 31, 2014		1,098,875		$	7.14		-	$	-
Granted		29,500		$	9.25		-	$	-
Vested		(27,500	)	$	4.02		-	$	-
Forfeited		(80,375	)	$	6.90		-	$	-
Nonvested at March 31, 2015		1,020,500		$	7.30		-	$	-
Granted		23,818		$	12.24		8,897	$	39.34
Vested		(11,250	)	$	7.32		-	$	-
Nonvested at June 30, 2015		1,033,068		$	7.41		8,897	$	39.34
Nonvested at September 30, 2015		1,033,068		$	7.41		8,897	$	39.34

For the three months ended September 30, 2015 and 2014, the Company recorded $175 and $198, respectively, in selling, general and administrative expenses for restricted stock awards. For the nine months ended September 30, 2015 and 2014, the Company recorded $292 and $322, respectively, in selling, general and administrative expenses for restricted stock awards. As of September 30, 2015, total compensation cost related to unvested restricted stock not yet recognized was $58. The cost will be amortized on a straight-line basis over the remaining weighted-average vesting period of one month.

The Company granted equity-settled performance shares (“PS”) to certain executives. PS awards provide the recipient the right to receive a certain number of shares of the Company’s common stock in the future, which depends on the Company’s level of achievement of net revenue and EBITDA growth as compared to the net revenue and EBITDA growth of the members of a specified peer group of companies over a three year period. For the three months ended September 30, 2015 and 2014, the Company recorded $482 and $69, respectively, in selling, general and administrative expenses related to PS awards. For the nine months ended September 30, 2015 and 2014, the Company recorded $1,431 and $744, respectively, in selling, general, and administrative expenses related to PS awards.

The Company granted cash-settled performance share units (“PSU”) to certain executives. PSU awards provide the recipient the right to receive the cash value of a certain number of shares of the Company’s common stock in the future, which depends on the Company’s level of achievement of net revenue and EBITDA growth as compared to the net revenue and EBITDA growth of the members of a specified peer group of companies over a three year period. As of September 30, 2015, there were no PSU awards outstanding. For the three and nine months ended September 30, 2014, the Company recorded $34 and $645, respectively, in selling, general and administrative expenses for PSU awards.