Stock Plans (Tables)

12 Months Ended

Dec. 31, 2014

Stock Plans

Schedule of share-based compensation expense

	Year ended December 31,
	2014			2013			2012
				(in thousands)
Cost of sales	$	2,456		$	1,446		$	1,467
Selling, general, and administrative	11,859			8,339			9,677
Research and development	4,498			3,347			2,709
Share-based compensation expense before tax	18,813			13,132			13,853
Income tax benefit	(6,011		)	(4,367		)	(4,849		)
Net share-based compensation expense	$	12,802		$	8,765		$	9,004

Summary of unrecognized share-based compensation costs

The following table summarizes information about unrecognized share-based compensation costs at December 31, 2014:

	Unrecognized		Weighted
	Share-Based		Average Period
	Compensation		Expected to be
	Costs		Recognized
	(in thousands)		(in years)
Stock option awards	$	9,939	2.0
Restricted stock units	9,980		2.5
Restricted stock awards	17,501		2.8
Performance share units	2,855		3.3
Performance share awards	152		0.4
Total unrecognized share-based compensation cost	$	40,427	2.5

Schedule of options, vested and expected to vest

Stock options are awards issued to employees that entitle the holder to purchase shares of the Company’s stock at a fixed price. At December 31, 2014, options outstanding that have vested and are expected to vest were as follows:

				Weighted
	Number	Weighted		Average	Aggregate
	of	Average		Remaining	Intrinsic
	Shares	Exercise Price		Contractual Life	Value
	(in thousands)			(in years)	(in thousands)
Vested	1,409	$	30.76	5.2	$	10,127
Expected to vest	903	$	32.93	7.7	2,091
Total	2,312	$	31.61	6.2	$	12,218

Summary of stock option awards activity

			Weighted
	Number of		Average
	Shares		Exercise Price
	(in thousands)
Outstanding at December 31, 2011	2,106		$	25.58
Granted	704		32.55
Exercised	(351	)	15.39
Expired or forfeited	(137	)	35.88
Outstanding at December 31, 2012	2,322		$	28.63
Granted	539		32.68
Exercised	(149	)	14.74
Expired or forfeited	(114	)	35.22
Outstanding at December 31, 2013	2,598		$	29.98
Granted	509		33.05
Exercised	(561	)	23.88
Expired or forfeited	(155	)	36.22
Outstanding at December 31, 2014	2,391		$	31.65

Summary of information about stock options outstanding

The following table summarizes stock option information at December 31, 2014:

	Options Outstanding						Options Exercisable
				Weighted						Weighted
		Aggregate		Average	Weighted			Aggregate		Average	Weighted
Range of		Intrinsic		Remaining	Average			Intrinsic		Remaining	Average
Exercise Prices	Shares	Value		Contractual Life	Exercise Price		Shares	Value		Contractual Life	Exercise Price
	(in thousands)	(in thousands)		(in years)			(in thousands)	(in thousands)		(in years)
$8.82 – $17.48	386	$	8,769	1.3	$	12.15	386	$	8,769	1.3	$	12.15
$20.80 – $31.45	347	1,626		8.8	30.20		125	616		8.7	29.94
$31.91 – $48.04	1,429	2,000		6.9	34.14		669	742		6.4	34.63
$48.90 – $51.70	229	—		6.4	51.21		229	—		6.4	51.21
	2,391	$	12,395	6.2	$	31.65	1,409	$	10,127	5.2	$	30.76

Assumptions based on which fair value of each option granted was estimated using the Black-Scholes option-pricing model

	Year ended December 31,
	2014			2013			2012
Weighted average fair value	$	11.58		$	13.47		$	15.56
Dividend yield	0		%	0		%	0		%
Expected volatility factor(1)	44		%	49		%	59		%
Risk-free interest rate(2)	1.19		%	1.27		%	0.70		%
Expected life(in years)(3)	3.9			4.5			4.5

(1) Expected volatility is measured using historical daily price changes of the Company’s stock over the respective expected term of the options and the implied volatility derived from the market prices of the Company’s traded opt ions.

(2) The risk-free rate for periods within the contractual term of the stock options is based on the U.S. Treasury yield curve in effect at the time of grant.

(3) The expected life is the number of years the Company estimates that options will be out standing prior to exercise. The Company’s computation of expected life was determined using a lattice-based model incorporating historical post vest exercise and employee termination behavior.

Summary of information on options exercised

	Year ended December 31,
	2014		2013		2012
			(in thousands)
Cash received from options exercised	$	12,056	$	2,199	$	5,409
Intrinsic value of options exercised	$	8,390	$	2,509	$	6,800

Summary of restricted stock awards and restricted stock unit activity

			Weighted
			Average
	Number of		Grant Date
	Shares		Fair Value
	(in thousands)
Outstanding at December 31, 2011	618		$	33.61
Granted	324		32.62
Released	(167	)	20.60
Forfeitures	(82	)	34.98
Outstanding at December 31, 2012	693		$	36.11
Granted	798		33.16
Released	(207	)	32.44
Forfeitures	(126	)	34.33
Outstanding at December 31, 2013	1,158		$	34.93
Granted	395		34.18
Released	(183	)	38.65
Forfeitures	(133	)	33.66
Outstanding at December 31, 2014	1,237		$	34.27