Stock-Based Compensation

3 Months Ended

Mar. 31, 2014

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation

4. STOCK-BASED COMPENSATION

The following table summarizes the stock-based compensation expense related to stock options, restricted stock units (RSUs) and restricted stock for the three months ended March 31, 2014 and 2013, which was recognized as follows:

	Three Months Ended March 31,
(In thousands)	2014			2013
Stock-based compensation expense included in cost of sales	$	116		$	106
Selling, general and administrative expense		1,026			1,063
Research and development expense		915			1,063
Stock-based compensation expense included in operating expenses		1,941			2,126
Total stock-based compensation expense		2,057			2,232
Tax benefit for expense associated with non-qualified options		(284	)		(307	)
Total stock-based compensation expense, net of tax	$	1,773		$	1,925

The fair value of our stock options was estimated using the Black-Scholes model. The determination of the fair value of stock options on the date of grant using the Black-Scholes model is affected by our stock price as well as assumptions regarding a number of complex and subjective variables that may have a significant impact on the fair value estimate.

There were no options granted during the three months ended March 31, 2013. The weighted-average assumptions and value of options granted for the three months ended March 31, 2014 are summarized as follows:

	Three Months Ended March 31, 2014
Expected volatility		39.57	%
Risk-free interest rate		1.86	%
Expected dividend yield		1.38	%
Expected life (in years)		6.25
Weighted-average estimated value	$	9.28

The fair value of our RSUs is calculated using a Monte Carlo Simulation valuation method. No RSUs were granted, forfeited, or vested during the three months ended March 31, 2014 or 2013.

The fair value of restricted stock is equal to the closing price of our stock on the date of grant. No restricted stock was granted, forfeited, or vested during the three months ended March 31, 2014 or 2013.

Stock-based compensation expense recognized in our Consolidated Statements of Income for the three months ended March 31, 2014 and 2013 is based on options, RSUs and restricted stock ultimately expected to vest, and has been reduced for estimated forfeitures. Estimated forfeitures for stock options were based upon historical experience and approximate 2.5% annually. We estimated a 0% forfeiture rate for our RSUs and restricted stock due to the limited number of recipients and historical experience for these awards.

As of March 31, 2014, total compensation expense related to non-vested stock options, RSUs and restricted stock not yet recognized was approximately $16.4 million, which is expected to be recognized over an average remaining recognition period of 2.5 years.

The following table is a summary of our stock options outstanding as of December 31, 2013 and March 31, 2014 and the changes that occurred during the three months ended March 31, 2014:

(In thousands, except per share amounts)	Number of Options			Weighted Avg. Exercise Price		Weighted Avg. Remaining Contractual Life In Years		Aggregate Intrinsic Value
Options outstanding, December 31, 2013		6,358		$	24.43		6.60	$	25,878
Options granted		2		$	26.03
Options cancelled/forfeited		(61	)	$	25.16
Options exercised		(78	)	$	19.71
Options outstanding, March 31, 2014		6,221		$	24.48		6.35	$	14,478
Options exercisable, March 31, 2014		3,826		$	24.84		4.93	$	8,526

The aggregate intrinsic values in the table above represent the total pre-tax intrinsic value (the difference between the closing price of our stock on the last trading day of the quarter and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on March 31, 2014. The aggregate intrinsic value will change based on the fair market value of our stock.

The total pre-tax intrinsic value of options exercised during the three months ended March 31, 2014 was $0.5 million.