Stock-Based Compensation (Tables)

3 Months Ended

Jun. 30, 2013

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock-Based Compensation Expense

The Company accounts for its stock-based compensation at fair value. The following table summarizes stock-based compensation expense by financial statement line item for the three months ended June 30, 2013 and 2012 (in thousands):


	Three months ended June 30,
	2013		2012
Cost of revenues	$	205	$	170
Research and development		575		562
Selling, general and administrative		1,355		1,262

Total	$	2,135	$	1,994

Schedule of Weighted Average Assumptions used in Black-Scholes Valuation Model for Stock Options Granted

The weighted-average assumptions used in the Black-Scholes valuation model for stock options granted during the three months ended June 30, 2013 and 2012 are as follows:


	Three months ended June 30,
	2013			2012
Expected volatility		74.6	%		72.0	%
Risk-free interest rate		1.7	%		0.9	%
Expected life (years)		5.9			5.9
Dividend yield		None			None