Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2015

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation Expense

We record stock-based compensation expense (including stock options, restricted stock and employee stock purchase plan) to the same departments where cash compensation is recorded as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
		2015		2014		2015		2014
Costs of revenue	$	271	$	243	$	538	$	382
Selling and marketing		112		477		605		751
Research and development		594		485		1,182		754
General and administrative		619		700		1,885		1,066
Total stock-based compensation expense	$	1,596	$	1,905	$	4,210	$	2,953

Assumptions Used to Determine the Fair Value of Options Granted under Employee Stock-Based Compensation Arrangements

We estimate the fair value of options granted under our employee stock-based compensation arrangements at the date of grant using the following weighted-average expected assumptions:

	Six Months Ended June 30,
		2015		2014
Dividend yield	None		None
Volatility		50%		63%
Risk-free interest rate		1.69%		1.96%
Expected life (years)		5.7		5.6