Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

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

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



	Year Ended December 31,
(In thousands)	2018		2017		2016
Cost of sales	$	84	$	71	$	57
Research and development expenses	744		551		541
Selling, general and administrative expenses:
Employees	6,491		7,368		7,095
Outside directors	1,501		3,953		2,631
Total employee and director stock-based compensation expense	$	8,820	$	11,943	$	10,324

Income tax benefit	$	1,870	$	2,954	$	3,102

Assumptions Used and Weighted Average Fair Value of Stock Option Grants

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:



	Year Ended December 31,
	2018			2017			2016
Weighted average fair value of grants	$	14.26		$	19.61		$	17.96
Risk-free interest rate	2.51		%	1.75		%	1.36		%
Expected volatility	33.09		%	34.25		%	41.38		%
Expected life in years	4.53			4.52			4.55

Stock Option Activity

Stock option activity was as follows:



	2018							2017							2016
	Number of Options (in 000's)		Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in 000's)		Number of Options (in 000's)		Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in 000's)		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 beginning of the year	520		$	42.56				652		$	39.27				648		$	30.50
Granted	119		44.95					92		62.70					243		49.67
Exercised	(35	)	24.67			$	744	(56	)	25.72			$	2,140	(239	)	26.09			$	9,933
Forfeited/canceled/expired	(7	)	27.74					(168	)	46.44					—		—
Outstanding at end of the year ⁽¹⁾	597		$	44.27	4.08	$	758	520		$	42.56	4.25	$	5,607	652		$	39.27	4.78	$	16,553
Vested and expected to vest at the end of the year ⁽¹⁾	597		$	44.27	4.08	$	758	520		$	42.56	4.25	$	5,607	652		$	39.27	4.78	$	16,548
Exercisable at the end of the year ⁽¹⁾	430		$	42.30	3.43	$	758	381		$	36.39	3.72	$	5,607	363		$	30.21	3.88	$	12,511

⁽¹⁾

The aggregate intrinsic value represents the total pre-tax value (the difference between our closing stock price on the last trading day of 2018, 2017, and 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 December 31, 2018, 2017, and 2016. This amount will change based on the fair market value of our stock.

Significant Option Groups Outstanding and Related Weighted Average Exercise Price and Life Information

Significant option groups outstanding at December 31, 2018 and the related weighted average exercise price and life information were as follows:



	Options Outstanding				Options Exercisable
Range of Exercise Prices	Number Outstanding (in 000’s)	Weighted-Average Remaining Contractual Term (in years)	Weighted-Average Exercise Price		Number Exercisable (in 000’s)	Weighted-Average Exercise Price
$18.25 to $20.55	134	3.35	$	19.63	134	$	19.63
$35.28 to $44.95	200	4.50	41.04		81	35.28
$51.38 to $65.54	263	4.14	59.31		215	59.03
	597	4.08	$	44.27	430	$	42.30

Non-Vested Restricted Stock Awards Activity

Non-vested restricted stock award activity was as follows:



	2018				2017				2016
	Shares (in 000’s)		Weighted-Average Grant Date Fair Value		Shares (in 000’s)		Weighted-Average Grant Date Fair Value		Shares (in 000’s)		Weighted-Average Grant Date Fair Value
Non-vested at beginning of the year	162		$	61.19	153		$	57.43	225		$	51.31
Granted	167		42.65		133		64.14		77		63.30
Vested	(109	)	56.16		(119	)	59.67		(146	)	51.10
Forfeited	(16	)	54.16		(5	)	60.11		(3	)	60.17
Non-vested at end of the year	204		$	49.23	162		$	61.19	153		$	57.43

Detailed Information Regarding Active Stock Incentive Plans

Detailed information regarding our active Stock Incentive Plans was as follows at December 31, 2018:



Name	Approval Date	Initial Shares Available for Grant Under the Plan	Remaining Shares Available for Grant Under the Plan	Outstanding Shares Granted Under the Plan
2003 Stock Incentive Plan	6/18/2003	1,000,000	—	14,391
2006 Stock Incentive Plan	6/13/2006	1,000,000	—	51,092
2010 Stock Incentive Plan	6/15/2010	1,000,000	—	198,971
2014 Stock Incentive Plan	6/12/2014	1,100,000	—	520,273
2018 Stock Incentive Plan	6/4/2018	1,000,000	969,150	15,850
			969,150	800,577