Stock-Based Compensation (Tables)

6 Months Ended

Sep. 30, 2012

Stock-Based Compensation [Abstract]

Schedule of Weighted-Average Assumptions Used to Estimate the Fair Value of Stock Options

The fair value of the options granted is estimated as of the grant date using the Black-Scholes option-pricing model assuming the weighted-average assumptions listed in the following tables:

	Three Months Ended September 30,
	Employee Stock Purchase  Plans
	2012			2011
Expected life (years)		0.5			0.5
Risk-free interest rate		0.2	%		0.2	%
Volatility		50	%		55	%
Dividend yield		—	%		—	%
Weighted average fair value	$	1.50		$	1.92

The Company did not grant options during the three months ended September 30, 2012 and 2011.

	Six Months Ended September 30,
	Employee Stock Options						Employee Stock Purchase Plans
	2012			2011			2012			2011
Expected life (years)		4.5			3.8			0.5			0.5
Risk-free interest rate		0.7	%		1.4	%		0.2	%		0.2	%
Volatility		54	%		48	%		50	%		55	%
Dividend yield		—	%		—	%		—	%		—	%
Weighted average fair value	$	2.47		$	3.83		$	1.50		$	1.92

Summary of Stock-Based Compensation Expense of Stock Options and Restricted Stock Units

The following table summarizes stock-based compensation expense related to stock options and restricted stock units (in thousands):

	Three Months Ended September 30,				Six Months Ended September 30,
	2012		2011		2012		2011
Stock-based compensation expense by type of award
Stock options and warrants	$	601	$	992	$	2,089	$	2,561
Restricted stock units		7,031		2,103		13,151		4,709
Total stock-based compensation		7,632		3,095		15,240		7,270
Stock-based compensation expensed from inventory		2		29		83		32
Total stock-based compensation expense	$	7,634	$	3,124	$	15,323	$	7,302

Summary of Stock-Based Compensation Expense

The following table summarizes stock-based compensation expense as it relates to the Company’s statement of operations (in thousands):

	Three Months Ended September 30,				Six Months Ended September 30,
	2012		2011		2012		2011
Stock-based compensation expense by cost centers
Cost of revenues	$	175	$	69	$	355	$	177
Research and development		3,714		1,726		7,919		4,114
Selling, general and administrative		3,743		1,300		6,966		2,979
Total stock-based compensation	$	7,632	$	3,095	$	15,240	$	7,270
Stock-based compensation expensed from inventory		2		29		83		32
Total stock-based compensation expense	$	7,634	$	3,124	$	15,323	$	7,302