Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2014

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

Weighted average assumptions used to estimate fair value of stock options granted and stock purchase rights under ESPP

The weighted average assumptions used to estimate the fair value of stock purchase rights under the ESPP are as follows:

	Three Months Ended March 31,
	2014		2013
ESPP
Volatility	47	%	58	%
Expected term (years)	1.1		1.5
Risk free interest rate	0.2	%	0.2	%
Expected dividend yield	—	%	—	%

Compensation costs included in statement of income for all stock-based compensation arrangements

The compensation cost that has been included in the statement of operations for all stock-based compensation arrangements was as follows (in thousands):

	Three Months Ended March 31,
	2014		2013
Sales, marketing and administrative expense	$	7,186	$	6,424
Research and development expense	465		342
Cost of goods sold	113		21
Total stock-based compensation expense	$	7,764	$	6,787