Stock-Based Compensation Expense (Tables)

6 Months Ended

Jun. 30, 2013

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

Effect of Recording Stock-Based Compensation Expense

The effect of recording stock-based compensation expense for the three and six months ended June 30, 2013 and 2012 is as follows (in thousands):

	Three Months Ended				Six Months Ended
	June 30, 2013		June 30, 2012		June 30, 2013		June 30, 2012
Cost of revenues	$	80	$	248	$	134	$	398
Research, development and other related costs	981		1,952		2,070		3,664
Selling, general and administrative	4,064		3,013		5,468		5,207
Total stock-based compensation expense	$	5,125	$	5,213	$	7,672	$	9,269

Stock-Based Compensation Expense Categorized by Equity Components

Stock-based compensation expense categorized by various equity components for the three and six months ended June 30, 2013 and 2012 is summarized in the table below (in thousands):

	Three Months Ended				Six Months Ended
	June 30, 2013		June 30, 2012		June 30, 2013		June 30, 2012
Employee stock options	$	2,913	$	3,148	$	4,948	$	5,910
Restricted stock awards and units	1,842		1,613		1,817		2,403
Employee stock purchase plan	370		452		907		956
Total stock-based compensation expense	$	5,125	$	5,213	$	7,672	$	9,269

Schedule of Assumptions Used To Value Options Granted

The following assumptions were used to value the options granted:

	Three Months Ended				Six Months Ended
	June 30, 2013		June 30, 2012		June 30, 2013	June 30, 2012
Expected life (in years)	5.0		3.7		5.0	3.7
Risk-free interest rate	1.4	%	0.6	%	0.8 - 1.4%	0.6 - 0.8%
Dividend yield	3.5	%	2.7	%	2.3 - 3.5%	2.2 - 2.7%
Expected volatility	58.9	%	63.0	%	58.9% - 59.5%	63.0 - 66.4%