Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2017

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation Expense Related to Stock Options, Performance Stock Units (PSUs), Restricted Stock Units (RSUs) and Restricted Stock

The following table summarizes the stock-based compensation expense related to stock options, performance stock units (PSUs), restricted stock units (RSUs) and restricted stock for the three and nine months ended September 30, 2017 and 2016, which was recognized as follows:

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
(In thousands)	2017			2016			2017			2016
Stock-based compensation expense included in cost of sales	$	97		$	88		$	281		$	282
Selling, general and administrative expense		994			765			3,018			2,322
Research and development expense		743			639			2,274			1,997
Stock-based compensation expense included in operating expenses		1,737			1,404			5,292			4,319
Total stock-based compensation expense		1,834			1,492			5,573			4,601
Tax benefit for expense associated with non-qualified options, PSUs, RSUs and restricted stock		(402	)		(218	)		(1,215	)		(643	)
Total stock-based compensation expense, net of tax	$	1,432		$	1,274		$	4,358		$	3,958

Summary of Stock Options Outstanding

The following table is a summary of our stock options outstanding as of December 31, 2016 and September 30, 2017 and the changes that occurred during the nine months ended September 30, 2017:

(In thousands, except per share amounts)	Number of Stock Options			Weighted Avg. Exercise Price		Weighted Avg. Remaining Contractual Life In Years		Aggregate Intrinsic Value
Stock options outstanding, December 31, 2016		6,338		$	22.14		5.63	$	16,972
Stock options granted		—		$	—
Stock options exercised		(358	)	$	18.44
Stock options forfeited		(54	)	$	17.49
Stock options expired		(90	)	$	27.31
Stock options outstanding, September 30, 2017		5,836		$	22.33		4.92	$	20,669
Stock options vested and expected to vest, September 30, 2017		5,836		$	22.33		4.92	$	20,669
Stock options exercisable, September 30, 2017		4,311		$	24.02		3.99	$	10,845

Summary of Weighted-Average Assumptions and Value of Options Granted

The weighted-average assumptions and value of options granted during the three and nine months ended September 30, 2016 were as follows:

	Three Months Ended			Nine Months Ended
	September 30,			September 30,
	2016			2016
Expected volatility		34.55	%		34.66	%
Risk-free interest rate		1.20	%		1.28	%
Expected dividend yield		1.83	%		1.88	%
Expected life (in years)		6.21			6.24
Weighted-average estimated value	$	5.64		$	5.50

Summary of PSUs, RSUs and Restricted Stock Outstanding

The following table is a summary of our PSUs, RSUs and restricted stock outstanding as of December 31, 2016 and the changes that occurred during the nine months ended September 30, 2017:

(In thousands, except per share amounts)	Number of Shares			Weighted Avg. Grant Date Fair Value
Unvested PSUs, RSUs and restricted stock outstanding, December 31, 2016		519		$	20.51
PSUs, RSUs and restricted stock granted		526		$	22.23
PSUs, RSUs and restricted stock vested		(4	)	$	18.00
PSUs, RSUs and restricted stock forfeited		(21	)	$	20.88
Unvested PSUs, RSUs and restricted stock outstanding, September 30, 2017		1,020		$	21.40