Stock-Based Compensation (Tables)

3 Months Ended

Mar. 27, 2015

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

Schedule of Compensation Expense Included in the Consolidated Statements of Comprehensive Income

Stock-based compensation expense included in our consolidated statements of comprehensive income was as follows:

	Three Months Ended
(In thousands)	March 27, 2015			March 28, 2014
Cost of sales	$	407		$	467
Research and development expense	8,943			10,273
Selling, general, and administrative expense	10,975			12,607
Pre-tax stock-based compensation expense	20,325			23,347
Less: income tax benefit	(5,621		)	(6,194		)
Net stock-based compensation expense	$	14,704		$	17,153

Schedule of Assumptions Used to Estimate Fair Value of RSUs

The assumptions used to estimate the fair value of the RSU awards granted under our stock-based compensation plans were as follows:

	Three Months Ended
	March 27, 2015			March 28, 2014
RSUs:
Risk-free interest rate	0.7		%	0.6		%
Dividend yield	2.1		%	1.9		%
Weighted-average estimated fair value	$	32.20		$	30.40

Summary of Activity for Restricted Stock Units and Performance Based Restricted Stock Units

A summary of activity for our RSUs and PRSUs for the three months ended March 27, 2015 and information regarding RSUs and PRSUs outstanding and expected to vest as of March 27, 2015 is as follows:

(In thousands, except per share amounts and terms)	Number of Shares		Weighted-Average Grant-Date Fair Market Value Per Share		Weighted-Average Remaining Contractual Term (in Years)	Aggregate Intrinsic Value (1)
Outstanding, December 31, 2014	5,506		$	34.00
Grants	92		$	34.00
Vested	(222	)	$	38.94
Forfeited/Cancelled	(79	)	$	33.88
Outstanding, March 27, 2015	5,297		$	33.80	1.2	$	235,136
Vested and expected to vest, March 27, 2015	4,792		$	33.80	1.2	$	212,699

(1) Aggregate intrinsic value represents the closing price per share of our stock on March 27, 2015, multiplied by the number of RSUs and market-based PRSUs outstanding or vested and expected to vest as of March 27, 2015.

Summary of Stock Option Activity

A summary of stock option activity for the three months ended March 27, 2015 and information regarding stock options outstanding, exercisable, and vested and expected to vest as of March 27, 2015 is as follows:

(In thousands, except per share amounts and terms)	Number of Shares		Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term (in Years)	Aggregate Intrinsic Value (1)
Outstanding, December 31, 2014	2,074		$	32.60
Grants	—		$	—
Exercises	(104	)	$	20.40
Forfeited/Cancelled/Expired	(17	)	$	32.37
Outstanding, March 27, 2015	1,953		$	33.26	5.1	$	21,741
Exercisable, March 27, 2015	1,524		$	32.75	4.6	$	17,732
Vested and expected to vest, March 27, 2015	1,931		$	33.25	5.1	$	21,518

(1) For those stock options with an exercise price below the closing price per share on March 27, 2015, aggregate intrinsic value represents the difference between the exercise price and the closing price per share of our common stock on March 27, 2015, multiplied by the number of stock options outstanding, exercisable, or vested and expected to vest as of March 27, 2015.