Share-based Compensation Expense (Tables)

3 Months Ended

Apr. 01, 2012

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

Share-based compensation expense for all stock awards

Share-based compensation expense for all stock awards consists of the following (in thousands):

	Three Months Ended
	April 1, 2012			April 3, 2011
Cost of product revenue	$	1,812		$	1,512
Cost of service and other revenue	17			210
Research and development	7,427			7,728
Selling, general and administrative	13,773			12,589
Share-based compensation expense before taxes	23,029			22,039
Related income tax benefits	(7,823		)	(7,761		)
Share-based compensation expense, net of taxes	$	15,206		$	14,278

Assumptions used to estimate the fair value per share of options granted and employee stock purchase rights granted

The assumptions used for the specified reporting periods and the resulting estimates of weighted-average fair value per share of options granted and for stock purchased under the ESPP for those periods are as follows:

	Three Months Ended
	April 1, 2012	April 3, 2011
Stock Options:
Risk-free interest rate	0.74%	2.23%
Expected volatility	43%	43%
Expected term	4.7 years	5.5 years
Expected dividends	—	—
ESPP:
Risk-free interest rate	0.09 - 0.13%	0.18 - 0.28%
Expected volatility	53 - 64%	43 - 46%
Expected term	0.5 - 1.0 years	0.5 - 1.0 years
Expected dividends	—	—