Note 10 - Stock Based Compensation

6 Months Ended

Jun. 30, 2016

Notes to Financial Statements

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

( 10 ) 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 three and six months ended June 30, 2016 was $13.82. The weighted-average fair value per share for the stock options granted to employees during the three and six months ended June 30, 2015 were $12.24 and $10.59, respectively.

For the three months ended June 30, 2016 and 2015, the Company recorded $972 and $733, respectively, in “Selling, general and administrative expenses” for stock options. For the six months ended June 30, 2016 and 2015, the Company recorded $1,824 and $1,338, respectively, in “Selling, general and administrative expenses” for stock options. As of June 30, 2016, the total compensation cost related to unvested stock options not yet recognized was $7,172. 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, 2015		1,631,913		$	19.17
Exercised		(44,279	)		9.47
Forfeited or expired		(5,250	)		16.45
Outstanding at March 31, 2016		1,582,384			19.45
Granted		20,264			45.12
Exercised		(165,210	)		9.30
Outstanding at June 30, 2016		1,437,438			20.98
Exercisable at June 30, 2016		527,324		$	13.78

The aggregate intrinsic values for all stock options exercised for the three and six months ended June 30, 2016 were $6,668 and $8,022, respectively. The aggregate intrinsic values for all stock options exercised for the three and six months ended June 30, 2015 were $2,083 and $7,422, respectively. The aggregate intrinsic values for all stock options outstanding and exercisable as of June 30, 2016 were $44,198 and $20,013, 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, 2015		922,658		$	10.35		178		$	46.91
Vested during period		(14,875	)		8.11		-			-
Forfeited		(5,250	)		7.76		-			-
Nonvested at March 31, 2016		902,533			10.40		178			46.91
Granted		20,264			13.82		10,640			45.12
Vested during period		(12,683	)		8.49		(178	)		46.91
Nonvested at June 30, 2016		910,114		$	10.66		10,640		$	45.12

For the three months ended June 30, 2016 and 2015, the Company recorded $161 and $117, respectively, in “Selling, general and administrative expenses” for restricted stock awards. For the six months ended June 30, 2016 and 2015, the Company recorded $166 and $117, respectively, in “Selling, general and administrative expenses” for restricted stock awards. As of June 30, 2016, total compensation cost related to unvested restricted stock not yet recognized was $320. The cost will be amortized on a straight-line basis over the remaining weighted-average vesting period of 0.3 years.

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 June 30, 2016 and 2015, the Company recorded $631 and $477, respectively, in “Selling, general and administrative expenses” related to these PS awards. For the six months ended June 30, 2016 and 2015, the Company recorded $1,310 and $949, respectively, in “Selling, general, and administrative expenses” related to PS awards.