STOCK-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2018

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

Summary Of Employee Stock-Based Compensation Expense

Stock-based compensation expense - all related to employees and members of the Board of Directors - recognized under the authoritative guidance was as follows:

	Years Ended December 31,
	2018		2017		2016
	(In thousands)
Selling, general and administrative	$	18,721	$	19,785	$	15,829
Research and development	1,609		1,273		1,048
Cost of goods sold	449		492		433
Total stock-based compensation expense	20,779		21,550		17,310
Total estimated tax benefit related to stock-based compensation expense	10,430		15,448		10,569
Net effect on net income	$	10,349	$	6,102	$	6,741

Summary Of Weighted-Average Assumptions

The following weighted-average assumptions were used in the calculation of fair value:

	Years Ended December 31,
	2018	2017	2016
Dividend yield	0%	0%	0%
Expected volatility	28%	30%	29%
Risk free interest rate	2.79%	2.18%	1.94%
Expected life of option from grant date	8 years	8 years	8 years

Summary Of Stock Option Activity

The following table summarizes the Company’s stock option activity.

			Weighted Average Exercise Price		Weighted Average Contractual Term in Years	Aggregate Intrinsic Value
	Shares
Stock Options	(In thousands)					(In thousands)
Outstanding at January 1, 2018	1,739		$	23.84
Granted	140		56.23
Exercised	(426	)	20.57
Forfeited or Expired	(5	)	—
Outstanding at December 31, 2018	1,448		$	27.91	3.79	$	26,451
Vested or expected to vest at December 31, 2018	1,448		$	27.91	3.79	$	26,451
Exercisable at December 31, 2018	1,117		$	22.47	3.01	$	25,278

Summary Of Restricted Stock, Performance Stock, and Contract Stock

The following table summarizes the Company’s awards of restricted stock, performance stock and contract stock for the year ended December 31, 2018.

	Restricted Stock Awards				Performance Stock and Contract Stock Awards
	Shares		Weighted Average Grant Date Fair Value Per Share		Shares		Weighted Average Grant Date Fair Value Per Share
	(In thousands)				(In thousands)
Unvested, January 1, 2018	451		$	37.79	172		$	33.61
Granted	261		56.77		164		56.23
Adjustments for performance achievement related to award target	—		—		40		21.42
Cancellations	(56	)	45.51		(14	)	—
Released	(239	)	37.13		(203	)	55.81
Vested but not released	—		—		(74	)	42.94
Unvested, December 31, 2018	417		$	48.97	85		$	45.56