Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2016

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

Schedule of Stock-based Compensation Expense

Stock-based compensation expense by income statement caption and the related income tax benefit were as follows:



	Three Months Ended June 30,				Six Months Ended June 30,
(In thousands)	2016		2015		2016		2015
Cost of sales	$	15	$	10	$	29	$	19
Research and development expenses	137		106		273		211
Selling, general and administrative expenses:
Employees	1,731		1,535		3,576		3,006
Outside directors	594		373		1,092		747
Total stock-based compensation expense	$	2,477	$	2,024	$	4,970	$	3,983

Income tax benefit	$	736	$	574	$	1,469	$	1,134

Schedule of Stock Option Activity

Stock option activity was as follows:



	Number of Options (in 000's)		Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in 000's)
Outstanding at December 31, 2015	648		$	30.50
Granted	244		49.67
Exercised	(104	)	24.44			$	3,619
Forfeited/canceled/expired	—		—
Outstanding at June 30, 2016 ⁽¹⁾	788		$	37.22	5.13	$	27,606
Vested and expected to vest at June 30, 2016⁽¹⁾	788		$	37.22	5.13	$	27,597
Exercisable at June 30, 2016 ⁽¹⁾	462		$	28.13	4.34	$	20,376

⁽¹⁾

The aggregate intrinsic value represents the total pre-tax value (the difference between our closing stock price on the last trading day of the second quarter of 2016 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had they all exercised their options on June 30, 2016. This amount will change based on the fair market value of our stock.

Schedule of Black Scholes Assumptions

The assumptions we utilized in the Black-Scholes option pricing model and the resulting weighted average fair value of stock option grants were the following:



	Three Months Ended June 30,						Six Months Ended June 30,
	2016			2015			2016			2015
Weighted average fair value of grants	$	—		$	—		$	17.96		$	24.77
Risk-free interest rate	—		%	—		%	1.36		%	1.38		%
Expected volatility	—		%	—		%	41.38		%	43.50		%
Expected life in years	0.00			0.00			4.55			4.56

Schedule of Non-vested Restricted Stock Awards Activity

Non-vested restricted stock award activity was as follows:



	Shares (in 000's)		Weighted-Average Grant Date Fair Value
Non-vested at December 31, 2015	225		$	51.31
Granted	38		51.78
Vested	(43	)	46.73
Forfeited	(2	)	56.69
Non-vested at June 30, 2016	218		$	52.25